what is unstable presentation

  • Mammary Glands
  • Fallopian Tubes
  • Supporting Ligaments
  • Reproductive System
  • Gametogenesis
  • Placental Development
  • Maternal Adaptations
  • Menstrual Cycle
  • Antenatal Care
  • Small for Gestational Age
  • Large for Gestational Age
  • RBC Isoimmunisation
  • Prematurity
  • Prolonged Pregnancy
  • Multiple Pregnancy
  • Miscarriage
  • Recurrent Miscarriage
  • Ectopic Pregnancy
  • Hyperemesis Gravidarum
  • Gestational Trophoblastic Disease
  • Breech Presentation
  • Abnormal lie, Malpresentation and Malposition
  • Oligohydramnios
  • Polyhydramnios
  • Placenta Praevia
  • Placental Abruption
  • Pre-Eclampsia
  • Gestational Diabetes
  • Headaches in Pregnancy
  • Haematological
  • Obstetric Cholestasis
  • Thyroid Disease in Pregnancy
  • Epilepsy in Pregnancy
  • Induction of Labour
  • Operative Vaginal Delivery
  • Prelabour Rupture of Membranes
  • Caesarean Section
  • Shoulder Dystocia
  • Cord Prolapse
  • Uterine Rupture
  • Amniotic Fluid Embolism
  • Primary PPH
  • Secondary PPH
  • Psychiatric Disease
  • Postpartum Contraception
  • Breastfeeding Problems
  • Primary Dysmenorrhoea
  • Amenorrhoea and Oligomenorrhoea
  • Heavy Menstrual Bleeding
  • Endometriosis
  • Endometrial Cancer
  • Adenomyosis
  • Cervical Polyps
  • Cervical Ectropion
  • Cervical Intraepithelial Neoplasia + Cervical Screening
  • Cervical Cancer
  • Polycystic Ovary Syndrome (PCOS)
  • Ovarian Cysts & Tumours
  • Urinary Incontinence
  • Genitourinary Prolapses
  • Bartholin's Cyst
  • Lichen Sclerosus
  • Vulval Carcinoma
  • Introduction to Infertility
  • Female Factor Infertility
  • Male Factor Infertility
  • Female Genital Mutilation
  • Barrier Contraception
  • Combined Hormonal
  • Progesterone Only Hormonal
  • Intrauterine System & Device
  • Emergency Contraception
  • Pelvic Inflammatory Disease
  • Genital Warts
  • Genital Herpes
  • Trichomonas Vaginalis
  • Bacterial Vaginosis
  • Vulvovaginal Candidiasis
  • Obstetric History
  • Gynaecological History
  • Sexual History
  • Obstetric Examination
  • Speculum Examination
  • Bimanual Examination
  • Amniocentesis
  • Chorionic Villus Sampling
  • Hysterectomy
  • Endometrial Ablation
  • Tension-Free Vaginal Tape
  • Contraceptive Implant
  • Fitting an IUS or IUD

Abnormal Fetal lie, Malpresentation and Malposition

Original Author(s): Anna Mcclune Last updated: 1st December 2018 Revisions: 12

  • 1 Definitions
  • 2 Risk Factors
  • 3.2 Presentation
  • 3.3 Position
  • 4 Investigations
  • 5.1 Abnormal Fetal Lie
  • 5.2 Malpresentation
  • 5.3 Malposition

The lie, presentation and position of a fetus are important during labour and delivery.

In this article, we will look at the risk factors, examination and management of abnormal fetal lie, malpresentation and malposition.

Definitions

  • Longitudinal, transverse or oblique
  • Cephalic vertex presentation is the most common and is considered the safest
  • Other presentations include breech, shoulder, face and brow
  • Usually the fetal head engages in the occipito-anterior position (the fetal occiput facing anteriorly) – this is ideal for birth
  • Other positions include occipito-posterior and occipito-transverse.

Note: Breech presentation is the most common malpresentation, and is covered in detail here .

what is unstable presentation

Fig 1 – The two most common fetal presentations: cephalic and breech.

Risk Factors

The risk factors for abnormal fetal lie, malpresentation and malposition include:

  • Multiple pregnancy
  • Uterine abnormalities (e.g fibroids, partial septate uterus)
  • Fetal abnormalities
  • Placenta praevia
  • Primiparity

Identifying Fetal Lie, Presentation and Position

The fetal lie and presentation can usually be identified via abdominal examination. The fetal position is ascertained by vaginal examination.

For more information on the obstetric examination, see here .

  • Face the patient’s head
  • Place your hands on either side of the uterus and gently apply pressure; one side will feel fuller and firmer – this is the back, and fetal limbs may feel ‘knobbly’ on the opposite side

Presentation

  • Palpate the lower uterus (above the symphysis pubis) with the fingers of both hands; the head feels hard and round (cephalic) and the bottom feels soft and triangular (breech)
  • You may be able to gently push the fetal head from side to side

The fetal lie and presentation may not be possible to identify if the mother has a high BMI, if she has not emptied her bladder, if the fetus is small or if there is polyhydramnios .

During labour, vaginal examination is used to assess the position of the fetal head (in a cephalic vertex presentation). The landmarks of the fetal head, including the anterior and posterior fontanelles, indicate the position.

what is unstable presentation

Fig 2 – Assessing fetal lie and presentation.

Investigations

Any suspected abnormal fetal lie or malpresentation should be confirmed by an ultrasound scan . This could also demonstrate predisposing uterine or fetal abnormalities.

Abnormal Fetal Lie

If the fetal lie is abnormal, an external cephalic version (ECV) can be attempted – ideally between 36 and 38 weeks gestation.

ECV is the manipulation of the fetus to a cephalic presentation through the maternal abdomen.

It has an approximate success rate of 50% in primiparous women and 60% in multiparous women. Only 8% of breech presentations will spontaneously revert to cephalic in primiparous women over 36 weeks gestation.

Complications of ECV are rare but include fetal distress , premature rupture of membranes, antepartum haemorrhage (APH) and placental abruption. The risk of an emergency caesarean section (C-section) within 24 hours is around 1 in 200.

ECV is contraindicated in women with a recent APH, ruptured membranes, uterine abnormalities or a previous C-section .

what is unstable presentation

Fig 3 – External cephalic version.

Malpresentation

The management of malpresentation is dependent on the presentation.

  • Breech – attempt ECV before labour, vaginal breech delivery or C-section
  • Brow – a C-section is necessary
  • If the chin is anterior (mento-anterior) a normal labour is possible; however, it is likely to be prolonged and there is an increased risk of a C-section being required
  • If the chin is posterior (mento-posterior) then a C-section is necessary
  • Shoulder – a C-section is necessary

Malposition

90% of malpositions spontaneously rotate to occipito-anterior as labour progresses. If the fetal head does not rotate, rotation and operative vaginal delivery can be attempted. Alternatively a C-section can be performed.

  • Usually the fetal head engages in the occipito-anterior position (the fetal occiput facing anteriorly) - this is ideal for birth

If the fetal lie is abnormal, an external cephalic version (ECV) can be attempted - ideally between 36 and 38 weeks gestation.

  • Breech - attempt ECV before labour, vaginal breech delivery or C-section

Found an error? Is our article missing some key information? Make the changes yourself here!

Once you've finished editing, click 'Submit for Review', and your changes will be reviewed by our team before publishing on the site.

We use cookies to improve your experience on our site and to show you relevant advertising. To find out more, read our privacy policy .

Privacy Overview

CookieDurationDescription
cookielawinfo-checkbox-analytics11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.

Search

Fetal Presentation, Position, and Lie (Including Breech Presentation)

  • Variations in Fetal Position and Presentation |

During pregnancy, the fetus can be positioned in many different ways inside the mother's uterus. The fetus may be head up or down or facing the mother's back or front. At first, the fetus can move around easily or shift position as the mother moves. Toward the end of the pregnancy the fetus is larger, has less room to move, and stays in one position. How the fetus is positioned has an important effect on delivery and, for certain positions, a cesarean delivery is necessary. There are medical terms that describe precisely how the fetus is positioned, and identifying the fetal position helps doctors to anticipate potential difficulties during labor and delivery.

Presentation refers to the part of the fetus’s body that leads the way out through the birth canal (called the presenting part). Usually, the head leads the way, but sometimes the buttocks (breech presentation), shoulder, or face leads the way.

Position refers to whether the fetus is facing backward (occiput anterior) or forward (occiput posterior). The occiput is a bone at the back of the baby's head. Therefore, facing backward is called occiput anterior (facing the mother’s back and facing down when the mother lies on her back). Facing forward is called occiput posterior (facing toward the mother's pubic bone and facing up when the mother lies on her back).

Lie refers to the angle of the fetus in relation to the mother and the uterus. Up-and-down (with the baby's spine parallel to mother's spine, called longitudinal) is normal, but sometimes the lie is sideways (transverse) or at an angle (oblique).

For these aspects of fetal positioning, the combination that is the most common, safest, and easiest for the mother to deliver is the following:

Head first (called vertex or cephalic presentation)

Facing backward (occiput anterior position)

Spine parallel to mother's spine (longitudinal lie)

Neck bent forward with chin tucked

Arms folded across the chest

If the fetus is in a different position, lie, or presentation, labor may be more difficult, and a normal vaginal delivery may not be possible.

Variations in fetal presentation, position, or lie may occur when

The fetus is too large for the mother's pelvis (fetopelvic disproportion).

The uterus is abnormally shaped or contains growths such as fibroids .

The fetus has a birth defect .

There is more than one fetus (multiple gestation).

what is unstable presentation

Position and Presentation of the Fetus

Toward the end of pregnancy, the fetus moves into position for delivery. Normally, the presentation is vertex (head first), and the position is occiput anterior (facing toward the pregnant person's spine) and with the face and body angled to one side and the neck flexed.

Variations in fetal presentations include face, brow, breech, and shoulder. Occiput posterior position (facing forward, toward the mother's pubic bone) is less common than occiput anterior position (facing backward, toward the mother's spine).

Variations in Fetal Position and Presentation

Some variations in position and presentation that make delivery difficult occur frequently.

Occiput posterior position

In occiput posterior position (sometimes called sunny-side up), the fetus is head first (vertex presentation) but is facing forward (toward the mother's pubic bone—that is, facing up when the mother lies on her back). This is a very common position that is not abnormal, but it makes delivery more difficult than when the fetus is in the occiput anterior position (facing toward the mother's spine—that is facing down when the mother lies on her back).

When a fetus faces up, the neck is often straightened rather than bent,which requires more room for the head to pass through the birth canal. Delivery assisted by a vacuum device or forceps or cesarean delivery may be necessary.

Breech presentation

In breech presentation, the baby's buttocks or sometimes the feet are positioned to deliver first (before the head).

When delivered vaginally, babies that present buttocks first are more at risk of injury or even death than those that present head first.

The reason for the risks to babies in breech presentation is that the baby's hips and buttocks are not as wide as the head. Therefore, when the hips and buttocks pass through the cervix first, the passageway may not be wide enough for the head to pass through. In addition, when the head follows the buttocks, the neck may be bent slightly backwards. The neck being bent backward increases the width required for delivery as compared to when the head is angled forward with the chin tucked, which is the position that is easiest for delivery. Thus, the baby’s body may be delivered and then the head may get caught and not be able to pass through the birth canal. When the baby’s head is caught, this puts pressure on the umbilical cord in the birth canal, so that very little oxygen can reach the baby. Brain damage due to lack of oxygen is more common among breech babies than among those presenting head first.

In a first delivery, these problems may occur more frequently because a woman’s tissues have not been stretched by previous deliveries. Because of risk of injury or even death to the baby, cesarean delivery is preferred when the fetus is in breech presentation, unless the doctor is very experienced with and skilled at delivering breech babies or there is not an adequate facility or equipment to safely perform a cesarean delivery.

Breech presentation is more likely to occur in the following circumstances:

Labor starts too soon (preterm labor).

The uterus is abnormally shaped or contains abnormal growths such as fibroids .

Other presentations

In face presentation, the baby's neck arches back so that the face presents first rather than the top of the head.

In brow presentation, the neck is moderately arched so that the brow presents first.

Usually, fetuses do not stay in a face or brow presentation. These presentations often change to a vertex (top of the head) presentation before or during labor. If they do not, a cesarean delivery is usually recommended.

In transverse lie, the fetus lies horizontally across the birth canal and presents shoulder first. A cesarean delivery is done, unless the fetus is the second in a set of twins. In such a case, the fetus may be turned to be delivered through the vagina.

quizzes_lightbulb_red

Copyright © 2024 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved.

  • Cookie Preferences

This icon serves as a link to download the eSSENTIAL Accessibility assistive technology app for individuals with physical disabilities. It is featured as part of our commitment to diversity and inclusion. M

Need to talk? Call 1800 882 436. It's a free call with a maternal child health nurse. *call charges may apply from your mobile

Is it an emergency? Dial 000 If you need urgent medical help, call triple zero immediately.

Share via email

There is a total of 5 error s on this form, details are below.

  • Please enter your name
  • Please enter your email
  • Your email is invalid. Please check and try again
  • Please enter recipient's email
  • Recipient's email is invalid. Please check and try again
  • Agree to Terms required

Error: This is required

Error: Not a valid value

Malpresentation

8-minute read

If you feel your waters break and you have been told that your baby is not in a head-first position, seek medical help immediately .

  • Malpresentation is when your baby is not facing head-first down the birth canal as birth approaches.
  • The most common type of malpresentation is breech — when your baby’s bottom or feet are facing downwards.
  • A procedure called external cephalic version can sometimes turn a breech baby into a head-first position at 36 weeks.
  • Most babies with malpresentation are born by caesarean, but you may be able to have a vaginal birth if your baby is breech.
  • There is a serious risk of cord prolapse if your waters break and your baby is not head-first.

What are presentation and malpresentation?

‘Presentation’ describes how your baby is facing down the birth canal. The ‘presenting part’ is the part of your baby’s body that is against the cervix .

The ideal presentation is head-first, with the crown (top) of the baby’s head against the cervix, with the chin tucked into the baby’s chest. This is called ‘vertex presentation’.

If your baby is in any other position, it’s called ‘malpresentation’. Malpresentation can mean your baby’s face, brow, buttocks, foot, back, shoulder, arms or legs or the umbilical cord are against the cervix.

It’s safest for your baby’s head to come out first. If any other body part goes down the birth canal first, the risks to you and your baby may be higher. Malpresentation increases the chance that you will have a more complex vaginal birth or a caesarean.

If my baby is not head-first, what position could they be in?

Malpresentation is caused by your baby’s position (‘lie’). There are different types of malpresentation.

Breech presentation

This is when your baby is lying with their bottom or feet facing down. Sometimes one foot may enter the birth canal first (called a ‘footling presentation’).

Breech presentation is the most common type of malpresentation.

Face presentation

This is when your baby is head-first but stretching their neck, with their face against the cervix.

Transverse lie

This is when your baby is lying sideways. Their back, shoulders, arms or legs may be the first to enter the birth canal.

Oblique lie

This is when your baby is lying diagonally. No particular part of their body is against the cervix.

Unstable lie

This is when your baby continually changes their position after 36 weeks of pregnancy.

Cord presentation

This is when the umbilical cord is against the cervix, between your baby and the birth canal. It can happen in any situation where your baby’s presenting part is not sitting snugly in your pelvis. It can become an emergency if it leads to cord prolapse (when the cord is born before your baby, potentially reducing placental blood flow to your baby).

What is malposition?

If your baby is lying head-first, the best position for labour is when their face is towards your back.

If your baby is facing the front of your body (posterior position) or facing your side (transverse position) this is called malposition. Transverse position is not the same as transverse lie. A transverse position means your labour may take a bit longer and you might feel more pain in your back. Often your baby will move into a better position before or during labour.

Why might my baby be in the wrong position?

Malpresentation may be caused by:

  • a low-lying placenta
  • too much or too little amniotic fluid
  • many previous pregnancies, making the muscles of the uterus less stable
  • carrying twins or more

Often no cause is found.

Is it likely that my baby will be in the wrong position?

Many babies are in a breech position during pregnancy. They usually turn head-first as pregnancy progresses, and more than 9 in 10 babies in Australia have a vertex presentation (ideal presentation, head-first) at birth.

You are more likely to have a malpresentation if:

  • this is your first baby
  • you are over 40 years old
  • you've had a previous breech baby
  • you go into labour prematurely

How is malpresentation diagnosed?

Malpresentation is normally diagnosed when your doctor or midwife examines you, from 36 weeks of pregnancy. If it’s not clear, it can be confirmed with an ultrasound.

Can my baby’s position be changed?

If you are 36 weeks pregnant , it may be possible to gently turn your baby into a head-first position. This is done by an obstetrician using a technique called external cephalic version (ECV).

Some people try different postures or acupuncture to correct malpresentation, but there isn’t reliable evidence that either of these work.

Will I need a caesarean if my baby has a malpresentation?

Most babies with a malpresentation close to birth are born by caesarean . You may be able to have a vaginal birth with a breech baby, but you will need to go to a hospital that can offer you and your baby specialised care.

If your baby is breech, an elective (planned) caesarean is safer for your baby than a vaginal birth in the short term. However, in the longer term their health will be similar, on average, regardless of how they were born.

A vaginal birth is safer for you than an elective caesarean. However, about 4 in 10 people planning a vaginal breech birth end up needing an emergency caesarean . If this happens to you, the risk of complications will be higher.

Your doctor can talk to you about your options. Whether it’s safe for you to try a vaginal birth will depend on many factors. These include how big your baby is, the position of your baby, the structure of your pelvis and whether you’ve had a caesarean in the past.

What are the risks if I have my baby when it’s not head-first?

If your waters break when your baby is not head-first, there is a risk of cord prolapse. This is an emergency.

Vaginal breech birth

Risks to your baby can include:

  • Erb’s palsy
  • fractures, dislocations or other injuries
  • bleeding in your baby’s brain
  • low Apgar scores
  • their head getting stuck – this is an emergency

Risks to you include:

  • blood loss or blood clots
  • infection in the wound
  • problems with the anaesthetic
  • damage to other organs nearby, such as your bladder
  • a higher chance of problems in future pregnancies
  • a longer recovery time than after a vaginal birth

Risks to your baby include:

  • trouble with breathing — this is temporary
  • getting a small cut during the surgery

Will I have a malpresentation in my future pregnancies?

If you had a malpresentation in one pregnancy, you have a higher chance of it happening again, but it won’t necessarily happen in future pregnancies. If you’re worried, it may help to talk to your doctor or midwife so they can explain what happened.

what is unstable presentation

Speak to a maternal child health nurse

Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call . Available 7am to midnight (AET), 7 days a week.

Learn more here about the development and quality assurance of healthdirect content .

Last reviewed: July 2022

Related pages

Labour complications.

  • Interventions during labour
  • Giving birth - stages of labour

Breech pregnancy

Search our site for.

  • Caesarean Section
  • Foetal Version

Need more information?

Top results

When a baby is positioned bottom-down late in pregnancy, this is called the breech position. Find out about 3 main types and safe birthing options.

Read more on Pregnancy, Birth & Baby website

Pregnancy, Birth & Baby

Breech Presentation at the End of your Pregnancy

Breech presentation occurs when your baby is lying bottom first or feet first in the uterus (womb) rather than the usual head first position. In early pregnancy, a breech position is very common.

Read more on RANZCOG - Royal Australian and New Zealand College of Obstetricians and Gynaecologists website

RANZCOG - Royal Australian and New Zealand College of Obstetricians and Gynaecologists

Breech presentation and turning the baby

In preparation for a safe birth, your health team will need to turn your baby if it is in a bottom first ‘breech’ position.

Read more on WA Health website

WA Health

External Cephalic Version for Breech Presentation - Pregnancy and the first five years

This information brochure provides information about an External Cephalic Version (ECV) for breech presentation

Read more on NSW Health website

NSW Health

Presentation and position of baby through pregnancy and at birth

Presentation and position refer to where your baby’s head and body is in relation to your birth canal. Learn why it’s important for labour and birth.

Even if you’re healthy and well prepared for childbirth, there’s always a chance of unexpected problems. Learn more about labour complications.

Pregnancy, Birth and Baby is not responsible for the content and advertising on the external website you are now entering.

Call us and speak to a Maternal Child Health Nurse for personal advice and guidance.

Need further advice or guidance from our maternal child health nurses?

1800 882 436

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.

© 2024 Healthdirect Australia Limited

This information is for your general information and use only and is not intended to be used as medical advice and should not be used to diagnose, treat, cure or prevent any medical condition, nor should it be used for therapeutic purposes.

The information is not a substitute for independent professional advice and should not be used as an alternative to professional health care. If you have a particular medical problem, please consult a healthcare professional.

Except as permitted under the Copyright Act 1968, this publication or any part of it may not be reproduced, altered, adapted, stored and/or distributed in any form or by any means without the prior written permission of Healthdirect Australia.

Support this browser is being discontinued for Pregnancy, Birth and Baby

Support for this browser is being discontinued for this site

  • Internet Explorer 11 and lower

We currently support Microsoft Edge, Chrome, Firefox and Safari. For more information, please visit the links below:

  • Chrome by Google
  • Firefox by Mozilla
  • Microsoft Edge
  • Safari by Apple

You are welcome to continue browsing this site with this browser. Some features, tools or interaction may not work correctly.

  • GP practice services
  • Health advice
  • Health research
  • Medical professionals

Health topics

Advice and clinical information on a wide variety of healthcare topics.

All health topics

Latest features

Allergies, blood & immune system

Bones, joints and muscles

Brain and nerves

Chest and lungs

Children's health

Cosmetic surgery

Digestive health

Ear, nose and throat

General health & lifestyle

Heart health and blood vessels

Kidney & urinary tract

Men's health

Mental health

Oral and dental care

Senior health

Sexual health

Signs and symptoms

Skin, nail and hair health

Travel and vaccinations

Treatment and medication

Women's health

Healthy living

Expert insight and opinion on nutrition, physical and mental health.

Exercise and physical activity

Healthy eating

Healthy relationships

Managing harmful habits

Mental wellbeing

Relaxation and sleep

Managing conditions

From ACE inhibitors for high blood pressure, to steroids for eczema, find out what options are available, how they work and the possible side effects.

Featured conditions

ADHD in children

Crohn's disease

Endometriosis

Fibromyalgia

Gastroenteritis

Irritable bowel syndrome

Polycystic ovary syndrome

Scarlet fever

Tonsillitis

Vaginal thrush

Health conditions A-Z

Medicine information

Information and fact sheets for patients and professionals. Find out side effects, medicine names, dosages and uses.

All medicines A-Z

Allergy medicines

Analgesics and pain medication

Anti-inflammatory medicines

Breathing treatment and respiratory care

Cancer treatment and drugs

Contraceptive medicines

Diabetes medicines

ENT and mouth care

Eye care medicine

Gastrointestinal treatment

Genitourinary medicine

Heart disease treatment and prevention

Hormonal imbalance treatment

Hormone deficiency treatment

Immunosuppressive drugs

Infection treatment medicine

Kidney conditions treatments

Muscle, bone and joint pain treatment

Nausea medicine and vomiting treatment

Nervous system drugs

Reproductive health

Skin conditions treatments

Substance abuse treatment

Vaccines and immunisation

Vitamin and mineral supplements

Tests & investigations

Information and guidance about tests and an easy, fast and accurate symptom checker.

About tests & investigations

Symptom checker

Blood tests

BMI calculator

Pregnancy due date calculator

General signs and symptoms

Patient health questionnaire

Generalised anxiety disorder assessment

Medical professional hub

Information and tools written by clinicians for medical professionals, and training resources provided by FourteenFish.

Content for medical professionals

FourteenFish training

  • Professional articles

Evidence-based professional reference pages authored by our clinical team for the use of medical professionals.

View all professional articles A-Z

Actinic keratosis

Bronchiolitis

Molluscum contagiosum

Obesity in adults

Osmolality, osmolarity, and fluid homeostasis

Recurrent abdominal pain in children

Medical tools and resources

Clinical tools for medical professional use.

All medical tools and resources

Malpresentations and malpositions

Peer reviewed by Dr Laurence Knott Last updated by Dr Colin Tidy, MRCGP Last updated 22 Jun 2021

Meets Patient’s editorial guidelines

  • Download Download Article PDF has been downloaded
  • Share via email

Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find one of our  health articles  more useful.

In this article :

Malpresentation, malposition.

Usually the fetal head engages in the occipito-anterior position (more often left occipito-anterior (LOA) rather than right) and then undergoes a short rotation to be directly occipito-anterior in the mid-cavity. Malpositions are abnormal positions of the vertex of the fetal head relative to the maternal pelvis. Malpresentations are all presentations of the fetus other than vertex.

Obstetrics - the pelvis and head

OBSTETRICS - THE PELVIS AND HEAD

Continue reading below

Predisposing factors to malpresentation include:

Prematurity.

Multiple pregnancy.

Abnormalities of the uterus - eg, fibroids.

Partial septate uterus.

Abnormal fetus.

Placenta praevia.

Primiparity.

Breech presentation

See the separate Breech Presentations article for more detailed discussion.

Breech presentation is the most common malpresentation, with the majority discovered before labour. Breech presentation is much more common in premature labour.

Approximately one third are diagnosed during labour when the fetus can be directly palpated through the cervix.

After 37 weeks, external cephalic version can be attempted whereby an attempt is made to turn the baby manually by manipulating the pregnant mother's abdomen. This reduces the risk of non-cephalic delivery 1 .

Maternal postural techniques have also been tried but there is insufficient evidence to support these 2 .

Many women who have a breech presentation can deliver vaginally. Factors which make this less likely to be successful include 3 :

Hyperextended neck on ultrasound.

High estimated fetal weight (more than 3.8 kg).

Low estimated weight (less than tenth centile).

Footling presentation.

Evidence of antenatal fetal compromise.

Transverse lie 4

When the fetus is positioned with the head on one side of the pelvis and the buttocks in the other (transverse lie), vaginal delivery is impossible.

This requires caesarean section unless it converts or is converted late in pregnancy. The surgeon may be able to rotate the fetus through the wall of the uterus once the abdominal wall has been opened. Otherwise, a transverse uterine incision is needed to gain access to a fetal pole.

Internal podalic version is no longer attempted.

Transverse lie is associated with a risk of cord prolapse of up to 20%.

Occipito-posterior position

This is the most common malposition where the head initially engages normally but then the occiput rotates posteriorly rather than anteriorly. 5.2% of deliveries are persistent occipito-posterior 5 .

The occipito-posterior position results from a poorly flexed vertex. The anterior fontanelle (four radiating sutures) is felt anteriorly. The posterior fontanelle (three radiating sutures) may also be palpable posteriorly.

It may occur because of a flat sacrum, poorly flexed head or weak uterine contractions which may not push the head down into the pelvis with sufficient strength to produce correct rotation.

As occipito-posterior-position pregnancies often result in a long labour, close maternal and fetal monitoring are required. An epidural is often recommended and it is essential that adequate fluids be given to the mother.

The mother may get the urge to push before full dilatation but this must be discouraged. If the head comes into a face-to-pubis position then vaginal delivery is possible as long as there is a reasonable pelvic size. Otherwise, forceps or caesarean section may be required.

Occipito-transverse position

The head initially engages correctly but fails to rotate and remains in a transverse position.

Alternatives for delivery include manual rotation of fetal head using Kielland's forceps, or delivery using vacuum extraction. This is inappropriate if there is any fetal acidosis because of the risk of cerebral haemorrhage.

Therefore, there must be provision for a failure of forceps delivery to be changed immediately to a caesarean. The trial of forceps is therefore often performed in theatre. Some centres prefer to manage by caesarean section without trial of forceps.

Face presentations

Face presents for delivery if there is complete extension of the fetal head.

Face presentation occurs in 1 in 1,000 deliveries 5 .

With adequate pelvic size, and rotation of the head to the mento-anterior position, vaginal delivery should be achieved after a long labour.

Backwards rotation of the head to a mento-posterior position requires a caesarean section.

Brow positions

The fetal head stays between full extension and full flexion so that the biggest diameter (the mento-vertex) presents.

Brow presentation occurs in 0.14% of deliveries 5 .

Brow presentation is usually only diagnosed once labour is well established.

The anterior fontanelle and super orbital ridges are palpable on vaginal examination.

Unless the head flexes, a vaginal delivery is not possible, and a caesarean section is required.

Further reading and references

  • Hofmeyr GJ, Kulier R, West HM ; External cephalic version for breech presentation at term. Cochrane Database Syst Rev. 2015 Apr 1;(4):CD000083. doi: 10.1002/14651858.CD000083.pub3.
  • Hofmeyr GJ, Kulier R ; Cephalic version by postural management for breech presentation. Cochrane Database Syst Rev. 2012 Oct 17;10:CD000051. doi: 10.1002/14651858.CD000051.pub2.
  • Management of Breech Presentation ; Royal College of Obstetricians and Gynaecologists (Mar 2017)
  • Szaboova R, Sankaran S, Harding K, et al ; PLD.23 Management of transverse and unstable lie at term. Arch Dis Child Fetal Neonatal Ed. 2014 Jun;99 Suppl 1:A112-3. doi: 10.1136/archdischild-2014-306576.324.
  • Gardberg M, Leonova Y, Laakkonen E ; Malpresentations - impact on mode of delivery. Acta Obstet Gynecol Scand. 2011 May;90(5):540-2. doi: 10.1111/j.1600-0412.2011.01105.x.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

Next review due: 21 Jun 2026

22 jun 2021 | latest version.

Last updated by

Peer reviewed by

symptom checker

Feeling unwell?

Assess your symptoms online for free

Fastest Obstetric, Gynecology and Pediatric Insight Engine

  • Abdominal Key
  • Anesthesia Key
  • Basicmedical Key
  • Otolaryngology & Ophthalmology
  • Musculoskeletal Key
  • Obstetric, Gynecology and Pediatric
  • Oncology & Hematology
  • Plastic Surgery & Dermatology
  • Clinical Dentistry
  • Radiology Key
  • Thoracic Key
  • Veterinary Medicine
  • Gold Membership

Malpresentations

Key Abbreviations Abdominal diameter AD American College of Obstetricians and Gynecologists ACOG Amniotic fluid index AFI Anteroposterior AP Biparietal diameter BPD Cerebral palsy CP Combined spinal-epidural CSE Computed tomography CT Confidence interval CI External cephalic version ECV Ex utero intrapartum treatment  EXIT Fetal heart rate FHR Internal podalic version IPV Magnetic resonance imaging MRI Occipitofrontal diameter OFD Odds ratio OR Perinatal mortality rate PMR Periventricular leukomalacia PVL Preterm premature rupture of the membranes PPROM Relative risk RR Term breech trial TBT Near term or during labor, the fetus normally assumes a vertical orientation, or lie, and a cephalic presentation, with the flexed fetal vertex presenting to the pelvis ( Fig. 17-1 ). However, in about 3% to 5% of singleton gestations at term, an abnormal lie, presentation, or flexed attitude occurs; such deviations constitute fetal malpresentations. The word malpresentation suggests the possibility of adverse consequences, and malpresentation is often associated with increased risk to both the mother and the fetus. In the early twentieth century, mal­presentation often led to a variety of maneuvers intended to facilitate vaginal delivery, including destructive operations lead­ing, predictably, to fetal death. Later, manual or instrumented attempts to convert the malpresenting fetus to a more favorable orientation were devised. Internal podalic version (IPV) followed by a complete breech extraction was once advocated as a solution to many malpresentation situations. However, like with most manipulative efforts to achieve vaginal delivery, IPV was associated with high fetal and maternal morbidity and mortality rates and has been largely abandoned. In contemporary practice, cesarean delivery has become the recommended mode of delivery in the malpresenting fetus. FIG 17-1 Frontal view of a fetus in a longitudinal lie with fetal vertex flexed on the neck. Clinical Circumstances Associated with Malpresentation Generally, factors associated with malpresentation include (1) diminished vertical polarity of the uterine cavity, (2) increased or decreased fetal mobility, (3) obstructed pelvic inlet, (4) fetal malformation, and (5) prematurity. The association of great parity with malpresentation is presumably related to laxity of maternal abdominal musculature and resultant loss of the normal vertical orientation of the uterine cavity. Placentation either high in the fundus or low in the pelvis ( Fig. 17-2 ) is another factor that diminishes the likelihood of a fetus assuming a longitudinal axis. Uterine myomata, intrauterine synechiae, and müllerian duct fusion abnormalities such as a septate uterus or uterine didelphys are similarly associated with a higher than expected rate of malpresentation. Because both prematurity and polyhydramnios permit increased fetal mobility, the probability of a noncephalic presentation is greater if preterm labor or rupture of the membranes occurs. Furthermore, preterm birth involves a fetus that is small relative to the maternal pelvis; therefore engagement and descent with labor or rupture of the membranes can occur despite a malpresentation. In contrast, conditions such as chromosomal aneuploidies, congenital myotonic dystrophy, joint contractures from various etiologies, arthrogryposis, oligohydramnios, and fetal neurologic dysfunction that result in decreased fetal muscle tone, strength, or activity are also associated with an increased incidence of fetal malpresentation. Finally, the cephalopelvic disproportion associated with severe fetal hydrocephalus or with a contracted maternal pelvis may be implicated as an etiology of malpresentation because normal engagement of the fetal head is prevented. FIG 17-2 Either the high fundal or low implantation of the placenta, as illustrated here, would normally be in the vertical orientation of the intrauterine cavity and increase the probability of a malpresentation. Abnormal Axial Lie The fetal lie indicates the orientation of the fetal spine relative to the spine of the mother. The normal fetal lie is longitudinal and by itself does not indicate whether the presentation is cephalic or breech. If the fetal spine or long axis crosses that of the mother, the fetus may be said to occupy a transverse or oblique lie ( Fig. 17-3 ), which may cause an arm, foot, or shoulder to be the presenting part ( Fig. 17-4 ). The lie may be termed unstable if the fetal membranes are intact and fetal mobility is increased, which results in frequent changes of lie and/or presentation. FIG 17-3 A fetus may lie on a longitudinal, oblique, or transverse axis, as illustrated. The lie does not indicate whether the vertex or the breech is closest to the cervix. FIG 17-4 This fetus lies in an oblique axis with an arm prolapsing. Abnormal fetal lie is diagnosed in approximately 1 in 300 cases, or 0.33% of pregnancies at term. Prematurity is often a factor, with abnormal lie reported to occur in about 2% of pregnancies at 32 weeks’ gestation—six times the rate found at term. Persistence of a transverse, oblique, or unstable lie beyond 37 weeks’ gestation requires a systematic clinical assessment and a plan for management; this is because rupture of the membranes without a fetal part filling the inlet of the pelvis poses an increased risk of cord prolapse, fetal compromise, and maternal morbidity if neglected. As noted, great parity, prematurity, contraction or deformity of the maternal pelvis, and abnormal placentation are the most commonly reported clinical factors associated with abnormal lie; however, it often happens that none of these factors are present. In fact, any condition that alters the normal vertical polarity of the intrauterine cavity will predispose to abnormal lie. Diagnosis of the abnormal lie may be made by palpation using Leopold maneuvers or by vaginal examination verified by ultrasound. Whereas routine use of Leopold maneuvers may be helpful, Thorp and colleagues found the sensitivity of Leopold maneuvers for the detection of malpresentation to be only 28%, and the positive predictive value was only 24% compared with immediate ultrasound verification. Others have observed prenatal detection in as few as 41% of cases before labor. Adaptations have been made to the Leopold maneuvers that may improve detection of an abnormal lie or presentation. The Sharma modified Leopold maneuver and the Sharma right and left lateral maneuvers in the original report demonstrated improved diagnostic accuracy; they detected vertex presenting occipitoanterior (95% vs. 84.4%, P = .04), posterior presentations (96.3% vs. 66.6%, P = .00012), and breech presentations correctly more often than with traditional Leopold maneuvers. These maneuvers use the forearms in addition to the hands and fingers. As with any abdominal palpation technique, limitations on accuracy are to be expected in the obese patient and in a patient with uterine myomata. The ready availability of ultrasound in most clinical settings is of benefit, and its use can obviate the vagaries of the abdominal palpation techniques. In all situations, early diagnosis of malpresentation is of benefit . A reported fetal loss rate of 9.2% with an early diagnosis, versus a loss rate of 27.5% with a delayed diagnosis, indicates that early diagnosis improves fetal outcome. Reported perinatal mortality rates for unstable or transverse lie (corrected for lethal malformations and extreme prema­turity) vary from 3.9% to 24%, with maternal mortality as high as 10%. Maternal deaths are usually related to infection after premature rupture of membranes (PROM), hemorrhage secondary to abnormal placentation, complications of operative intervention for cephalopelvic disproportion, or traumatic delivery. Fetal loss of phenotypically and chromosomally normal gestations at ages considered to be viable is primarily associated with delayed interventions, prolapsed cord, or traumatic delivery. Cord prolapse occurs 20 times as often with abnormal lie as it does with a cephalic presentation. Management of a Singleton Gestation Safe vaginal delivery of a fetus from an abnormal axial lie is not generally possible. A search for the etiology of the malpresentation is always indicated. A transverse/oblique or unstable lie late in the third trimester necessitates ultrasound examination to exclude a major fetal malformation and abnormal placentation. Fortunately, most cases of major fetal anomalies or abnormal placentation can now be diagnosed long before the third trimester. Phelan and colleagues reported 29 patients with transverse lie diagnosed at or beyond 37 weeks’ gestation and managed expectantly, and 83% (24 of 29) spontaneously converted to breech (9 of 24) or vertex (15 of 24) before labor; however, the overall cesarean delivery rate was 45%, with two cases of cord prolapse, one uterine rupture, and one neonatal death. External cephalic version (ECV) is recommended at 36 to 37 weeks to help diminish the risk of adverse outcome. In cases of an abnormal lie, the risk of fetal death varies with the obstetric intervention. Fetal mortality should approach zero for cesarean birth but has been reported to be as high as 10% in older reports and between 25% and 90% when IPV and breech extraction are performed. ECV has been found to be safe and relatively efficacious and is further discussed later in this chapter. If external version is unsuccessful or unavailable, if spontaneous rupture of the membranes occurs, or if active labor has begun with an abnormal lie, cesarean delivery is the treatment of choice for the potentially viable infant. There is no place for IPV and breech extraction in the management of transverse or oblique lie or in an unstable presentation in a singleton pregnancy because of the unacceptably high rate of fetal and maternal complications. A persistent abnormal axial lie, particularly if accompanied by ruptured membranes, also alters the choice of uterine incision at cesarean delivery. A low transverse (Kerr) uterine incision has many surgical advantages and is generally the preferred approach for cesarean delivery for an abnormal lie (see Chapter 19 ). Because up to 25% of transverse incisions may require vertical extension for delivery of an infant from an abnormal lie, and the lower uterine segment is often poorly developed and insufficiently broad such that a traumatic delivery of the presenting part is made more difficult, other uterine incisions may be considered. A “J” or “T” extension of the low transverse incision results in a uterine scar that is more susceptible to subsequent rupture due to poor vascularization. Therefore in the uncommon case of a transverse or oblique lie with a poorly developed lower uterine segment, when a transverse incision is deemed unfeasible or inadequate, a vertical incision (low vertical or classical) may be a reasonable alternative. Intraoperative cephalic version may allow the use of a low transverse incision, but ruptured membranes or oligohydramnios may make this difficult. Uterine relaxing agents such as inhalational anesthetics or intravenous (IV) nitroglycerin may improve success of these maneuvers if the difficulty is attributable to a contracted uterine fundus. Deflection Attitudes Attitude refers to the position of the fetal head in relation to the neck. The normal attitude of the fetal head during labor is one of full flexion with the fetal chin against the upper chest. Deflexed attitudes include various degrees of deflection or even extension of the fetal neck and head ( Fig. 17-5 ), leading to, for example, face or brow presentations. Spontaneous conversion to a more normal, flexed attitude or further extension of an intermediate deflection to a fully extended position commonly occurs as labor progresses owing to resistance exerted by the bony pelvis and soft tissues. Although safe vaginal delivery is possible in many cases, experience indicates that cesarean delivery may be the most appropriate alternative when arrest of progress is observed. FIG 17-5 The normal “attitude” ( top ) shows the fetal vertex flexed on the neck. Partial deflexion ( middle ) shows the fetal vertex intermediate between flexion and extension. Full deflexion ( lower ) shows the fetal vertex completely extended with the face presenting. Face Presentation A face presentation is characterized by a longitudinal lie and full extension of the fetal neck and head with the occiput against the upper back ( Fig. 17-6 ). The fetal chin (mentum) is chosen as the point of designation during vaginal examination. For example, a fetus presenting by the face whose chin is in the right posterior quadrant of the maternal pelvis would be called a right mentum posterior ( Fig. 17-7 ). The reported incidence of face presentation ranges from 0.14% to 0.54% and averages about 0.2%, or 1 in 500 live births overall. The reported perinatal mortality rate, corrected for nonviable malformations and extreme prematurity, varies from 0.6% to 5% and averages about 2% to 3%. FIG 17-6 This fetus with the vertex completely extended on the neck enters the maternal pelvis in a face presentation. The cephalic prominence would be palpable on the same side of the maternal abdomen as the fetal spine. FIG 17-7 The point of designation from digital examination in the case of a face presentation is the fetal chin relative to the maternal pelvis. Left, right mentum posterior (RMP); middle, mentum anterior (MA); right, left mentum transverse (LMT). All clinical factors known to increase the general rate of malpresentation have been implicated in face presentation; many infants with a face presentation have malformations. Anencephaly, for instance, is found in about one third of cases of face presentation. Fetal goiter and tumors of the soft tissues of the head and neck may also cause deflexion of the head. Frequently observed maternal factors include a contracted pelvis or cephalopelvic disproportion in 10% to 40% of cases. In a review of face presentation, Duff found that one of these etiologic factors was found in up to 90% of cases. Early recognition of the face presentation is important, and the diagnosis can be suspected when abdominal palpation finds the fetal cephalic prominence on the same side of the maternal abdomen as the fetal back ( Fig. 17-8 ); however, face presen­tation is more often discovered by vaginal examination. In practice, fewer than 1 in 20 infants with face presentation is diagnosed by abdominal examination. In fact, only half of these infants are found by any means to have a face presentation before the second stage of labor, and half of the remaining cases are undiagnosed until delivery. However, perinatal mortality may be higher with late diagnosis. FIG 17-8 Palpation of the maternal abdomen in the case of a face presentation should find the fetal cephalic prominence on the side away from the fetal small parts, instead of on the same side, as in the case of a normally flexed fetal neck and head. Mechanism of Labor Knowledge of the early mechanism of labor for face presentation is incomplete. Many infants with a face presentation probably begin labor in the less extended brow position. With descent into the pelvis, the forces of labor press the fetus against maternal tissues; subsequent flexion (to a vertex presentation) or full extension of the head on the spine (to a face presentation) then occurs. The labor of a face presentation must include engagement, descent, internal rotation generally to a mentum anterior position, and delivery by flexion as the chin passes under the symphysis ( Fig. 17-9 ). However, flexion of the occiput may not always occur, and delivery in the fully extended attitude may be common. FIG 17-9 Engagement, descent, and internal rotation remain cardinal elements of vaginal delivery in the case of a face presentation, but successful vaginal delivery of a term-size fetus presenting a face generally requires delivery by flexion under the symphysis from a mentum anterior position, as illustrated here. The prognosis for labor with a face presentation depends on the orientation of the fetal chin. At diagnosis, 60% to 80% of infants with a face presentation are mentum anterior, 10% to 12% are mentum transverse, and 20% to 25% are mentum posterior. Almost all average-sized infants presenting mentum anterior with adequate maternal pelvic dimensions will achieve spontaneous or assisted vaginal delivery. Furthermore, most mentum transverse infants will rotate to the mentum anterior position and will deliver vaginally, and even 25% to 33% of mentum posterior infants will rotate and deliver vaginally in the mentum anterior position. In a review of 51 cases of persistent face presentation, Schwartz and colleagues found that the mean birthweight of those infants in a mentum posterior position who did rotate and deliver vaginally was 3425 g, compared with 3792 g for those infants who did not rotate and deliver vaginally. Persistence of the mentum posterior position with an infant of normal size, however, makes safe vaginal delivery less likely. Overall, 70% to 80% of infants with a face presenting can be delivered vaginally, either spontaneously or by low forceps in the hands of a skilled operator, whereas 12% to 30% require cesarean delivery. Manual attempts to convert the face to a flexed attitude or to rotate a posterior position to a more favorable mentum anterior position are rarely successful and increase both maternal and fetal risks. Again, IPV and breech extraction for face presentation historically are associated with unacceptably high fetal loss rates. Maternal deaths from uterine rupture and trauma have also been documented. Thus contemporary management through spontaneous delivery and cesarean delivery for other obstetric indications as necessary are the preferred routes for both maternal and fetal safety. Prolonged labor is a common feature of face presentation and has been associated with an increased number of intrapartum deaths; therefore prompt attention to an arrested labor pattern is recommended. In the case of an average or small fetus, an adequate pelvis, and hypotonic labor, oxytocin may be considered. No absolute contraindication to oxytocin augmentation of hypotonic labor in face presentations exists, but an arrest of progress despite adequate labor should call for cesarean delivery. Worsening of the fetal condition in labor is common. Salzmann and colleagues observed a tenfold increase in fetal compromise with face presentation. Several other observers have also found that abnormal fetal heart rate (FHR) patterns occur more often with face presentation. Continuous intrapartum electronic FHR monitoring of a fetus with face presentation is considered mandatory, but extreme care must be exercised in the placement of an electrode because ocular or cosmetic damage is possible. If external Doppler heart rate monitoring is inadequate and an internal electrode is recommended, placement of the electrode on the fetal chin is often preferred. Contraindications to vaginal delivery of a face presentation include macrosomia, nonreassurance of FHR monitoring even without arrested or protracted labor, or an inadequate maternal pelvis; cesarean delivery has been reported in as many as 60% of cases of face presentation for these reasons. If cesarean delivery is warranted, care should be taken to flex the head gently, both to accomplish elevation of the head through the hysterotomy incision as well as to avoid potential cervical nerve damage to the neonate. Forced flexion may also result in fetal injury, especially with fetal goiter or neck tumors. Fetal laryngeal and tracheal edema that results from the pressure of the birth process might require immediate nasotracheal intubation. Nuchal tumors or simple goiters, fetal anomalies that might have caused the malpresentation, require expert neonatal management, including the possibility of an ex utero intrapartum treatment (EXIT) procedure, which establishes a fetal/neonatal airway before the umbilical cord is clamped. Identification of and planning for these particular circumstances in the prelabor setting are ideal. Brow Presentation A fetus in a brow presentation occupies a longitudinal axis with a partially deflexed cephalic attitude midway between full flexion and full extension ( Fig. 17-10 ). The frontal bones are the point of designation. If the anterior fontanel is on the mother’s left side, with the sagittal suture in the transverse pelvic axis, the fetus would be in a left frontum transverse position ( Fig. 17-11 ). The reported incidence of brow presentation varies widely, from 1 in 670 to 1 in 3433, averaging about 1 in 1500 deliveries. Brow presentation is detected more often in early labor before flexion occurs to a normal attitude. Less frequently, further extension results in a face presentation. FIG 17-10 This fetus is in a brow presentation in a frontum anterior position. The head is in an intermediate deflexion attitude. FIG 17-11 In brow presentation, the anterior fontanel (frontum) relative to the maternal pelvis is the point of designation. Left, fetus in left frontum transverse (LFT); middle, frontum anterior (FA); right, left frontum anterior (LFA). In 1976, the perinatal mortality rate corrected for lethal anomalies and very low birthweight varied from 1% to 8%. In a study of 88,988 deliveries, corrected perinatal mortality rates for brow presentations depended on the mode of delivery; a loss rate of 16%, the highest in this study, was associated with manipulative vaginal birth. In general, factors that delay engagement are associated with persistent brow presentation. Cephalopelvic disproportion, prematurity, and high parity are often found and have been implicated in more than 60% of cases of persistent brow presentation. Detection of a brow presentation by abdominal palpation is unusual in practice. More often, a brow presentation is detected on vaginal examination. As in the case of a face presentation, diagnosis in labor is more likely. Fewer than 50% of brow presentations are detected before the second stage of labor, and most of the remainder are undiagnosed until delivery. Frontum anterior is reportedly the most common position at diagnosis, occurring about twice as often as either transverse or posterior positions. Although the initial position at diagnosis may be of limited prognostic value, the cesarean delivery rate is higher with frontum transverse or frontum posterior than with frontum anterior positioning. A persistent brow presentation requires engagement and descent of the largest (mento-occipital) diameter of the fetal head. This process is possible only with a large pelvis or a small infant, or both. However, most brow presentations convert spontaneously by flexion or further extension to either a vertex or a face presentation and are then managed accordingly. The earlier the diagnosis is made, the more likely conversion will occur spontaneously. Fewer than half of fetuses with persistent brow presentations undergo spontaneous vaginal delivery, but in most cases, a trial of labor is not contraindicated. Prolonged labors have been observed in 33% to 50% of brow presentations, and secondary arrest is not uncommon. Forced conversion of the brow to a more favorable position with forceps is contraindicated, as are attempts at manual conversion. One unexpected cause of persistent brow presentation may be an open fetal mouth pressed against the vaginal wall, splinting the head and preventing either flexion or extension ( Fig. 17-12 ). Although this is rare in phenotypically normal fetuses, it needs to be considered in anomalous conditions of the fetus such as epignathus, a rare oropharyngeal teratoma. FIG 17-12 The open fetal mouth against the vaginal sidewall may brace the head in the intermediate deflexion attitude as shown here. Similar to face presentations, minimal manipulation yields the best results if the FHR pattern remains reassuring. Expectant management may be justified, preferably with a relatively large pelvis in relation to fetal size and adequate labor progress, according to one large study. If a brow presentation persists with a large baby, successful vaginal delivery is unlikely, and cesarean delivery may be most prudent. Radiographic or computed tomographic (CT) pelvimetry is not used clinically, and one report states that although 91% of cases with adequate pelvimetry converted to a vertex or a face presentation and delivered vaginally, 20% with some form of pelvic contracture did also. Therefore regardless of pelvic dimensions, consideration of a trial of labor with careful monitoring of maternal and fetal condition may be appropriate. As in the case of a face presentation, oxytocin may be used cautiously to correct hypotonic contractions, but prompt resumption of progress toward delivery should follow. Compound Presentation Whenever an extremity, most commonly an upper extremity, is found prolapsed beside the main presenting fetal part, the situation is referred to as a compound presentation ( Fig. 17-13 ). The reported incidence ranges from 1 in 377 to 1 in 1213 deliveries. The combination of an upper extremity and the vertex is the most common. FIG 17-13 The compound presentation of an upper extremity and the vertex illustrated here most often spontaneously resolves with further labor and descent. This diagnosis should be suspected with any arrest of labor in the active phase or failure to engage during active labor. Diagnosis is made on vaginal examination by discovery of an irregular mobile tissue mass adjacent to the larger presenting part. Recognition late in labor is common, and as many as 50% of persisting compound presentations are not detected until the second stage. Delay in diagnosis may not be detrimental because it is likely that only the persistent cases require intervention. Although maternal age, race, parity, and pelvic size have been associated with compound presentation, prematurity is the most consistent clinical finding. The very small premature fetus is at great risk of persistent compound presentation. In late pregnancy, ECV of a fetus in breech position increases the risk of a compound presentation. Older, uncontrolled studies report elevated perinatal mortality rates with a compound presentation, with an overall rate of 93 per 1000. Higher loss rates of 17% to 19% have been reported when the foot prolapses. As with other malpresentations, fetal risk is directly related to the method of management. A fetal mortality rate of 4.8% has been noted if no intervention is required compared with 14.4% with intervention other than cesarean delivery. A 30% fetal mortality rate has been observed with IPV and breech extraction. These figures may demonstrate selection bias because it is possible that more often, the difficult cases were chosen for manipulative intervention. When intervention is necessary, cesarean delivery appears to be the only safe choice. Fetal risk in compound presentation is specifically associated with birth trauma and cord prolapse. Cord prolapse occurs in 11% to 20% of cases, and it is the most frequent complication of this malpresentation. Cord prolapse probably occurs because the compound extremity splints the larger presenting part and results in an irregular fetal aggregate that incompletely fills the pelvic inlet. In addition to the hypoxic risk of cord prolapse, common fetal morbidity includes neurologic and musculoskeletal damage to the involved extremity. Maternal risks include soft tissue damage and obstetric laceration. Again, although laboring is not proscribed, the prolapsed extremity should not be manipulated. However, it may spontaneously retract as the major presenting part descends. Seventy-five percent of vertex/upper extremity combinations deliver spontaneously. Occult or obscured cord prolapse is possible, and therefore continuous electronic FHR monitoring is recommended. The primary indications for surgical intervention (i.e., cesarean delivery) are cord prolapse, nonreassuring FHR patterns, and arrest of labor. Cesarean delivery is the only appropriate clinical intervention for cord prolapse and nonreassuring FHR patterns because both version extraction and repositioning the prolapsed extremity are associated with adverse outcome and should be avoided. From 2% to 25% of compound presentations require cesarean delivery. Protraction of the second stage of labor and dysfunctional labor patterns have been noted to occur more frequently with persistent compound presentations. As in other malpresentations, spontaneous resolution occurs more often, and surgical intervention is less frequently necessary in those cases diagnosed early in labor. Small or premature fetuses are more likely to have persistent compound presentations but are also more likely to have a successful vaginal delivery. Persistent compound presentation with parts other than the vertex and hand in combination in a term-sized infant has a poor prognosis for safe vaginal delivery, and cesarean delivery is usually necessary. However, a simple compound presentation (e.g., hand) may be allowed to labor, if labor is progressing normally with reassuring fetal status. Breech Presentation The infant presenting as a breech occupies a longitudinal axis with the cephalic pole in the uterine fundus. This presentation occurs in 3% to 4% of labors overall, although it is found in 7% of pregnancies at 32 weeks and in 25% of pregnancies of less than 28 weeks’ duration. The three types of breech are noted in Table 17-1 . The infant in the frank breech position is flexed at the hips with extended knees (pike position). The complete breech is flexed at both joints (tuck position), and the footling or incomplete breech has one or both hips partially or fully extended ( Fig. 17-14 ). TABLE 17-1 BREECH CATEGORIES TYPE OVERALL % OF BREECHES RISK OF PROLAPSE (%) † PREMATURE (%) ‡ Frank 48-73 * † ‡ 0.5 38 Complete 4.6-11.5 † ‡ 4-6 12 Footling 12-38 ‡ 15-18 50   * Data from Collea JV, Chein C, Quilligan EJ. The randomized management of term frank breech presentation: a study of 208 cases. Am J Obstet Gynecol. 1980;137:235-244. † Data from Gimovsky ML, Wallace RL, Schifrin BS, Paul RH. Randomized management of the nonfrank breech presentation at term: a preliminary report. Am J Obstet Gynecol. 1983;146:34-40. ‡ Data from Brown L, Karrison T, Cibils LA. Mode of delivery and perinatal results in breech presentation. Am J Obstet Gynecol. 1994;171:28-34. FIG 17-14 The complete breech is flexed at the hips and flexed at the knees. The incomplete breech shows incomplete deflexion of one or both knees or hips. The frank breech is flexed at the hips and extended at the knees. The diagnosis of breech presentation may be made by abdominal palpation or vaginal examination and confirmed by ultrasound. Prematurity, fetal malformation, müllerian anomalies, and polar placentation are commonly observed causative factors. High rates of breech presentation are noted in certain fetal genetic disorders, including trisomies 13, 18, and 21; Potter syndrome; and myotonic dystrophy. Conditions that alter fetal muscular tone and mobility—such as increased and decreased amniotic fluid, for example—also increase the frequency of breech presentation. The breech head appears dolichocephalic on ultrasound, and for that reason, the biparietal diameter (BPD) appears small. However, the head circumference remains unaffected. This difference may be as much as 16+ days (95% confidence interval [CI], 14.3 to 18.1; P = .001). Whereas the contracted BPD may affect ultrasound-determined weight estimates of the fetus, an occipitofrontal diameter (OFD) to BPD ratio of greater than 1.3 in the absence of other indicators of growth delay signals the deformation characteristic of the breech-presenting fetus. Approximately 80% of breech fetuses will have a dolichocephalic contour, previously termed the “breech head.” The fundus of the uterus assumes a more elongated contour than the bowl-like developed lower uterine segment. Thus it is believed that forces external to the fetus are responsible for this head shape. Because both dolichocephaly and breech may be associated with a genetically and phenotypically anomalous fetus, it behooves the sonologist to perform a detailed survey of the fetal anatomy prior to assuming the presence of the “breech head.” Mechanism and Conduct of Labor and Vaginal Delivery The two most important elements for the safe conduct of vaginal breech delivery are continuous electronic FHR monitoring and noninterference until spontaneous delivery of the breech to the umbilicus has occurred. Early in labor, the capability for immediate cesarean delivery should be established. Anesthesia should be available, the operating room readied, and appropriate informed consent obtained (discussed later). Two obstetricians should be in attendance in addition to a pediatric team. Appropriate training and experience with vaginal breech delivery are fundamental to success. Although experience is becoming infinitely less common, simulation of breech deliveries will help to maintain these skills. The instrument table should be prepared in the customary manner, with the addition of Piper forceps and extra towels. No contraindication exists to epidural analgesia in labor, and many believe epidural anesthesia to be an asset in the control and conduct of the second stage. The infant presenting in the frank breech position usually enters the pelvic inlet in one of the diagonal pelvic diameters ( Fig. 17-15 ). Engagement has occurred when the bitrochanteric diameter of the fetus has progressed beyond the plane of the pelvic inlet, although by vaginal examination, the presenting part may be palpated only at a station of −2 to −4 (out of 5). As the breech descends and encounters the levator ani muscular sling, internal rotation usually occurs to bring the bitrochanteric diameter into the anteroposterior (AP) axis of the pelvis. The point of designation in a breech labor is the fetal sacrum ; therefore when the bitrochanteric diameter is in the AP axis of the pelvis, the fetal sacrum will lie in the transverse pelvic diameter ( Fig. 17-16 ). FIG 17-15 The breech typically enters the inlet with the bitrochanteric diameter aligned with one of the diagonal diameters, with the sacrum as the point of designation in the other diagonal diameter. This illustrates a left sacrum posterior alignment. FIG 17-16 With labor and descent, the bitrochanteric diameter generally rotates toward the anteroposterior axis, and the sacrum rotates toward the transverse axis. If normal descent occurs, the breech will present at the outlet and will begin to emerge, first as sacrum transverse, then rotating to sacrum anterior. This direction of rotation may reflect the greater capacity of the hollow of the posterior pelvis to accept the fetal chest and small parts. Crowning occurs when the bitrochanteric diameter passes under the pubic symphysis. It is important to emphasize that operator intervention is not yet needed or helpful, other than possibly to perform the episiotomy if indicated and to encourage maternal expulsive efforts. Premature or aggressive intervention may adversely affect the delivery in at least two ways. First, complete cervical dilation must be sustained for sufficient duration to retard retraction of the cervix and entrapment of the aftercoming fetal head. Rushing the delivery of the trunk may result in cervical retraction. Second, the safe descent and delivery of the breech infant must be the result of uterine and maternal expulsive forces only in order to maintain neck flexion. Any traction by the provider in an effort to speed delivery would encourage deflexion of the neck and result in the presentation of the larger occipitofrontal fetal cranial profile to the pelvic inlet ( Fig. 17-17 ). Such an event could be catastrophic. Rushed delivery also increases the risk of a nuchal arm, with one or both arms trapped behind the head above the pelvic inlet. Entrapment of a nuchal arm makes safe vaginal delivery much more difficult because it dramatically increases the aggregate size of delivering fetal parts that must egress vaginally. Safe breech delivery of an average-sized infant, therefore, depends predominantly on maternal expulsive forces and patience, not traction, from the provider. FIG 17-17 The fetus emerges spontaneously (A), whereas uterine contractions maintain cephalic flexion. Premature aggressive traction (B) encourages deflexion of the fetal vertex and increases the risk of head entrapment or nuchal arm entrapment. As the frank breech emerges further, the fetal thighs are typically flexed firmly against the fetal abdomen, often splinting and protecting the umbilicus and cord. The Pinard maneuver may be needed to facilitate delivery of the legs in a frank breech presentation. After delivery to the umbilicus has occurred, pressure is applied to the medial aspect of the knee, which causes flexion and subsequent delivery of the lower leg. Simultaneous to this, the fetal pelvis is rotated away from that side ( Fig. 17-18 ). This results in external rotation of the thigh at the hip, flexion of the knee, and delivery of one leg at a time. The dual movement of counterclockwise rotation of the fetal pelvis as the operator externally rotates the right thigh and clockwise rotation of the fetal pelvis as the operator externally rotates the fetal left thigh is most effective in facilitating delivery. The fetal trunk is then wrapped with a towel to provide secure support of the body while further descent results from expulsive forces from the mother. The operator primarily facilitates the delivery of the fetus by providing support and guiding the body through the introitus. The operator is not applying outward traction on the fetus, which might result in deflexion of the fetal head or nuchal arm. FIG 17-18 After spontaneous expulsion to the umbilicus, external rotation of each thigh (A) combined with opposite rotation of the fetal pelvis results in flexion of the knee and delivery of each leg (B). When the scapulae appear at the introitus, the operator may slip a hand over the fetal shoulder from the back ( Fig. 17-19 ); follow the humerus; and, with movement from medial to lateral, sweep first one and then the other arm across the chest and out over the perineum. Gentle rotation of the fetal trunk counterclockwise assists delivery of the right arm, and clockwise rotation assists delivery of the left arm (turning the body “into” the arm). This accomplishes delivery of the arms by drawing them across the fetal chest in a fashion similar to that used for delivery of the legs ( Fig. 17-20 ). These movements cause the fetal elbow to emerge first, followed by the forearm and hand. Once both arms have been delivered, if the vertex has remained flexed on the neck, the chin and face will appear at the outlet, and the airway may be cleared and suctioned ( Fig. 17-21 ). FIG 17-19 When the scapulae appear under the symphysis, the operator reaches over the left shoulder, sweeps the arm across the chest (A), and delivers the arm (B). FIG 17-20 Gentle rotation of the shoulder girdle facilitates delivery of the right arm. FIG 17-21 Following delivery of the arms, the fetus is wrapped in a towel for control and is slightly elevated. The fetal face and airway may be visible over the perineum. Excessive elevation of the trunk is avoided. With further maternal expulsive forces alone, spontaneous controlled delivery of the fetal head often occurs. If not, delivery may be accomplished with a simple manual effort to maximize flexion of the vertex using pressure on the fetal maxilla (not the mandible), the Mauriceau-Smellie-Veit maneuver, using gentle downward traction along with suprapubic pressure (Credé maneuver; Fig. 17-22 ). Although maxillary pressure facilitates flexion, the main force effecting delivery remains the mother. FIG 17-22 Cephalic flexion is maintained by pressure ( black arrow ) on the fetal maxilla, not the mandible. Often, delivery of the head is easily accomplished with continued expulsive forces from above and gentle downward traction. Alternatively, the operator may apply Piper forceps to the aftercoming head. The application requires very slight elevation of the fetal trunk by the assistant, while the operator kneels and applies the Piper forceps from beneath the fetus directly to the fetal head in the pelvis. Delivery of the breech presenting fetus, therefore, should occur on a table/bed capable of allowing the operators to correctly position themselves for the application of forceps. Direct access to the perineum is required. If a delivery bed is used, merely dropping the foot of the bed will be inadequate. The position of the operator for applying the forceps is depicted in Figure 17-23 , which also demonstrates how excessive elevation by the assistant may potentially cause harm to the neonate. Hyperextension of the fetal neck from excessive elevation of the fetal trunk, shown in Figure 17-23 , should be avoided because of the potential for spinal cord injury. FIG 17-23 Demonstration of incorrect assistance during the application of Piper forceps. The assistant hyperextends the fetal neck, a position that increases the risk for neurologic injury. Piper forceps are characterized by absence of pelvic curvature. This modification allows direct application to the fetal head and avoids conflict with the fetal body that would occur with the application of standard instruments from below. The assistant maintains control of the fetal body while the forceps are inserted into the vagina from beneath the fetus by the primary operator. The blade to be placed on the maternal left is held by the handle in the operator’s left hand; the blade is inserted with the operator’s right hand in the vagina along the left maternal sidewall and is placed against the right fetal parietal bone. The handle of the right blade is then held in the operator’s right hand and is inserted by the left hand along the right maternal sidewall and placed against the left fetal parietal bone. At this point, the assistant allows the fetal body to rest on the shank and handles of the forceps. Gentle downward traction on the forceps with the fetal trunk supported on the forceps shanks results in controlled delivery of the vertex ( Fig. 17-24 ). Forceps application controls the fetal head and prevents extension of the head on the neck. Application of Piper forceps to the aftercoming head may be advisable both to ensure control of the delivery and to maintain optimal operator proficiency in anticipation of deliveries that may require their use. FIG 17-24 The fetus may be laid on the forceps and delivered with gentle downward traction, as illustrated here. Arrest of spontaneous progress in labor with adequate uterine contractions necessitates consideration of cesarean delivery. Any evidence of fetal compromise or sustained cord compression on the basis of continuous electronic FHR monitoring also requires consideration of cesarean delivery. Vaginal interventions directed at facilitating delivery of the breech complicated by an arrest of spontaneous progress are discouraged because fetal and maternal morbidity and mortality are both greatly increased. However, if labor is deemed to be hypotonic by internally monitored uterine pressures, oxytocin is not contraindicated. Mechanisms of descent and delivery of the incomplete and the complete breech are not unlike those used for the frank breech described earlier; at least one leg may not require attention. The risk of cord prolapse or entanglement is greater, and hence the possibility of emergency cesarean delivery is increased. Furthermore, incomplete and complete breeches may not be as effective as cervical dilators as either the vertex or the larger aggregate profile of the thighs and buttocks of the frank breech. Thus the risk of entrapment of the aftercoming head is increased, and as a result, primary cesarean delivery is often advocated for nonfrank breech presentations. However, the randomized trial of Gimovsky and colleagues found vaginal delivery of the nonfrank breech to be reasonably safe. Contemporary Management of the Term Breech Debate has largely diminished about the proper management of the term breech. Much of the older data were derived from relatively few studies of varied methodologies, patient populations, and multiple retrospective cohort analyses, which are subject to bias. These reports indicated that the perinatal mortality rate for the vaginally delivered breech appears to be greater than for its cephalic counterpart, but much of the reported perinatal mortality rate associated with breech presentation was largely due to lethal anomalies and complications of prematurity, both of which are found more frequently among breech infants. Excluding anomalies and extreme prematurity, the corrected perinatal mortality reported by some investigators approached zero regardless of the method of delivery, whereas others found that even with exclusion of these factors, the term breech infant has been found to be at higher risk for birth trauma and asphyxia. To date, only three randomized trials have been reported. Although conclusions regarding the safety of breech vaginal delivery from a fetal standpoint may continue to vary, the practical reality today is that intentional vaginal breech delivery is rare. A summary of some of the reported complications is listed in Table 17-2 . Overall, consideration of a potential breech vaginal delivery must be mutually agreed on by the patient and the physician after complete informed consent is obtained. TABLE 17-2

Share this:

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)

Related posts:

  • Operative Vaginal Delivery
  • Placenta Accreta
  • Prolonged and Postterm Pregnancy
  • Mental Health and Behavioral Disorders in Pregnancy

what is unstable presentation

Stay updated, free articles. Join our Telegram channel

Comments are closed for this page.

what is unstable presentation

Full access? Get Clinical Tree

what is unstable presentation

  • Getting Pregnant
  • Registry Builder
  • Baby Products
  • Birth Clubs
  • See all in Community
  • Ovulation Calculator
  • How To Get Pregnant
  • How To Get Pregnant Fast
  • Ovulation Discharge
  • Implantation Bleeding
  • Ovulation Symptoms
  • Pregnancy Symptoms
  • Am I Pregnant?
  • Pregnancy Tests
  • See all in Getting Pregnant
  • Due Date Calculator
  • Pregnancy Week by Week
  • Pregnant Sex
  • Weight Gain Tracker
  • Signs of Labor
  • Morning Sickness
  • COVID Vaccine and Pregnancy
  • Fetal Weight Chart
  • Fetal Development
  • Pregnancy Discharge
  • Find Out Baby Gender
  • Chinese Gender Predictor
  • See all in Pregnancy
  • Baby Name Generator
  • Top Baby Names 2023
  • Top Baby Names 2024
  • How to Pick a Baby Name
  • Most Popular Baby Names
  • Baby Names by Letter
  • Gender Neutral Names
  • Unique Boy Names
  • Unique Girl Names
  • Top baby names by year
  • See all in Baby Names
  • Baby Development
  • Baby Feeding Guide
  • Newborn Sleep
  • When Babies Roll Over
  • First-Year Baby Costs Calculator
  • Postpartum Health
  • Baby Poop Chart
  • See all in Baby
  • Average Weight & Height
  • Autism Signs
  • Child Growth Chart
  • Night Terrors
  • Moving from Crib to Bed
  • Toddler Feeding Guide
  • Potty Training
  • Bathing and Grooming
  • See all in Toddler
  • Height Predictor
  • Potty Training: Boys
  • Potty training: Girls
  • How Much Sleep? (Ages 3+)
  • Ready for Preschool?
  • Thumb-Sucking
  • Gross Motor Skills
  • Napping (Ages 2 to 3)
  • See all in Child
  • Photos: Rashes & Skin Conditions
  • Symptom Checker
  • Vaccine Scheduler
  • Reducing a Fever
  • Acetaminophen Dosage Chart
  • Constipation in Babies
  • Ear Infection Symptoms
  • Head Lice 101
  • See all in Health
  • Second Pregnancy
  • Daycare Costs
  • Family Finance
  • Stay-At-Home Parents
  • Breastfeeding Positions
  • See all in Family
  • Baby Sleep Training
  • Preparing For Baby
  • My Custom Checklist
  • My Registries
  • Take the Quiz
  • Best Baby Products
  • Best Breast Pump
  • Best Convertible Car Seat
  • Best Infant Car Seat
  • Best Baby Bottle
  • Best Baby Monitor
  • Best Stroller
  • Best Diapers
  • Best Baby Carrier
  • Best Diaper Bag
  • Best Highchair
  • See all in Baby Products
  • Why Pregnant Belly Feels Tight
  • Early Signs of Twins
  • Teas During Pregnancy
  • Baby Head Circumference Chart
  • How Many Months Pregnant Am I
  • What is a Rainbow Baby
  • Braxton Hicks Contractions
  • HCG Levels By Week
  • When to Take a Pregnancy Test
  • Am I Pregnant
  • Why is Poop Green
  • Can Pregnant Women Eat Shrimp
  • Insemination
  • UTI During Pregnancy
  • Vitamin D Drops
  • Best Baby Forumla
  • Postpartum Depression
  • Low Progesterone During Pregnancy
  • Baby Shower
  • Baby Shower Games

Breech, posterior, transverse lie: What position is my baby in?

Layan Alrahmani, M.D.

Fetal presentation, or how your baby is situated in your womb at birth, is determined by the body part that's positioned to come out first, and it can affect the way you deliver. At the time of delivery, 97 percent of babies are head-down (cephalic presentation). But there are several other possibilities, including feet or bottom first (breech) as well as sideways (transverse lie) and diagonal (oblique lie).

Fetal presentation and position

During the last trimester of your pregnancy, your provider will check your baby's presentation by feeling your belly to locate the head, bottom, and back. If it's unclear, your provider may do an ultrasound or an internal exam to feel what part of the baby is in your pelvis.

Fetal position refers to whether the baby is facing your spine (anterior position) or facing your belly (posterior position). Fetal position can change often: Your baby may be face up at the beginning of labor and face down at delivery.

Here are the many possibilities for fetal presentation and position in the womb.

Medical illustrations by Jonathan Dimes

Head down, facing down (anterior position)

A baby who is head down and facing your spine is in the anterior position. This is the most common fetal presentation and the easiest position for a vaginal delivery.

This position is also known as "occiput anterior" because the back of your baby's skull (occipital bone) is in the front (anterior) of your pelvis.

Head down, facing up (posterior position)

In the posterior position , your baby is head down and facing your belly. You may also hear it called "sunny-side up" because babies who stay in this position are born facing up. But many babies who are facing up during labor rotate to the easier face down (anterior) position before birth.

Posterior position is formally known as "occiput posterior" because the back of your baby's skull (occipital bone) is in the back (posterior) of your pelvis.

Frank breech

In the frank breech presentation, both the baby's legs are extended so that the feet are up near the face. This is the most common type of breech presentation. Breech babies are difficult to deliver vaginally, so most arrive by c-section .

Some providers will attempt to turn your baby manually to the head down position by applying pressure to your belly. This is called an external cephalic version , and it has a 58 percent success rate for turning breech babies. For more information, see our article on breech birth .

Complete breech

A complete breech is when your baby is bottom down with hips and knees bent in a tuck or cross-legged position. If your baby is in a complete breech, you may feel kicking in your lower abdomen.

Incomplete breech

In an incomplete breech, one of the baby's knees is bent so that the foot is tucked next to the bottom with the other leg extended, positioning that foot closer to the face.

Single footling breech

In the single footling breech presentation, one of the baby's feet is pointed toward your cervix.

Double footling breech

In the double footling breech presentation, both of the baby's feet are pointed toward your cervix.

Transverse lie

In a transverse lie, the baby is lying horizontally in your uterus and may be facing up toward your head or down toward your feet. Babies settle this way less than 1 percent of the time, but it happens more commonly if you're carrying multiples or deliver before your due date.

If your baby stays in a transverse lie until the end of your pregnancy, it can be dangerous for delivery. Your provider will likely schedule a c-section or attempt an external cephalic version , which is highly successful for turning babies in this position.

Oblique lie

In rare cases, your baby may lie diagonally in your uterus, with his rump facing the side of your body at an angle.

Like the transverse lie, this position is more common earlier in pregnancy, and it's likely your provider will intervene if your baby is still in the oblique lie at the end of your third trimester.

Was this article helpful?

What to know if your baby is breech

diagram of breech baby, facing head-up in uterus

9 of the most jaw-dropping breech birth photos

baby with umbilical cord getting delivered

Cord prolapse during pregnancy

an illustration of cord prolapse during pregnancy

Augmentation of labor: Why it's used to speed up childbirth

woman in labor with healthcare provider

BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organizations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies .

Ahmad A et al. 2014. Association of fetal position at onset of labor and mode of delivery: A prospective cohort study. Ultrasound in obstetrics & gynecology 43(2):176-182. https://www.ncbi.nlm.nih.gov/pubmed/23929533 Opens a new window [Accessed September 2021]

Gray CJ and Shanahan MM. 2019. Breech presentation. StatPearls.  https://www.ncbi.nlm.nih.gov/books/NBK448063/ Opens a new window [Accessed September 2021]

Hankins GD. 1990. Transverse lie. American Journal of Perinatology 7(1):66-70.  https://www.ncbi.nlm.nih.gov/pubmed/2131781 Opens a new window [Accessed September 2021]

Medline Plus. 2020. Your baby in the birth canal. U.S. National Library of Medicine. https://medlineplus.gov/ency/article/002060.htm Opens a new window [Accessed September 2021]

Kate Marple

Where to go next

diagram of breech baby, facing head-up in uterus

what is unstable presentation

When a Person Is Told They Have an Unstable Lie

  • By: Gail Tully
  • January 29, 2020
  • Birth Anatomy , Pregnancy , Preparing for Birth

forward-leaning inversion

Lie means how the baby lies in the womb. The head-down baby is in a vertical lie, sometimes called cephalic to use a Latin term to mean the head is coming. Breech is an old English term to mean the baby’s pelvis is coming first. Both a head up (breech) and a head-down (cephalic) baby are in a vertical lie. When a baby is lying across the abdomen or sideways, we say baby is in a “ Transverse lie ”. An oblique lie is when baby’s body is diagonal in the womb. The head or pelvis is towards one hip and the opposite “pole” or end of the baby is under the opposite rib. A baby in an oblique lie might have their head by the right hip and their bottom beneath the left ribs, for instance.

Using Spinning Babies® techniques for an Unstable Lie

Forward-leaning Inversion

She wrote, “My 38-week baby had flipped head down twice (once from Spinning Babies® and once from a version [ECV] at the hospital), but wouldn’t stay that way- what’s considered unstable lie. I was 5 days away from having a version at the hospital, if it worked they would have induced me. If not, C-section.” About this time, I was able to call Crista and offer a plan for helping baby flip head down and gave her the name of a breech-skilled provider in our area.

Suggestions for Unstable Lie

side-lying release

Side-lying Release

Planning to wear the pregnancy belt and continue (one FLI a day) and Side-lying Releases (SLR) to keep him this way (and walking and sitting on the ball )- no ironing board inversions. Thank you, thank you, thank you!” I replied, “Such good news! Wow! Walk, walk walk! With a good stride and shoes. If you do decide to induce, please consider one FLI the morning before starting the IV. The SLR and FLI can support the normal progress of labor, whether natural or induced . Remember their helpfulness before getting frustrated or tired. Same for pain, as this combination of techniques will also help reduce pain in labor.” Crista agreed,  “Yes! There is no reason to induce now, so I’m just like every other pregnant lady waiting for labor to start. Thanks for the advice for during labor, I will do it! I loved that your approach is so physiological and practical. My super, by-the-book OBGYN even recommended Spinning Babies® and she is usually very skeptical of anything outside medical guidelines. I wish everybody knew how much control you can actually have over how your baby interacts with your body! I am a believer and am excited to use some of the techniques during labor. Please share my story. I can’t thank you enough.”

Helpful Links:

  • Find a Spinning Babies® Certified Parent Educator
  • Find a Spinning Babies® Aware Practitioner
  • Your Pregnancy Week-by-Week with Spinning Babies®
  • Products for Parents
  • Free Reading For Parents

Connect with Us

Sign up for our newsletter:, more information:.

Have any questions or concerns? Email us at [email protected]

Daily Essentials

Activities for pregnancy comfort and easier birth.

Global Library of Womens Medicine

An expert resource for medical professionals Provided FREE as a service to women’s health

The Global Library of Women’s Medicine EXPERT – RELIABLE - FREE Over 20,000 resources for health professionals

The Alliance for Global Women’s Medicine A worldwide fellowship of health professionals working together to promote, advocate for and enhance the Welfare of Women everywhere

International Federation of Gynecology and Obstetrics

An Educational Platform for FIGO

The Global Library of Women’s Medicine Clinical guidance and resources

A vast range of expert online resources. A FREE and entirely CHARITABLE site to support women’s healthcare professionals

The Global Academy of Women’s Medicine Teaching, research and Diplomates Association

  • Expert clinical guidance
  • Safer motherhood
  • Skills videos
  • Clinical films
  • Special textbooks
  • Ambassadors
  • Can you help us?
  • Introduction
  • Definitions
  • Complications
  • External Cephalic Version
  • Management of Labor And Delivery
  • Cesarean Delivery
  • Perinatal Outcome
  • Practice Recommendations
  • Study Assessment – Optional
  • Your Feedback

This chapter should be cited as follows: Okemo J, Gulavi E, et al , Glob. libr. women's med ., ISSN: 1756-2228; DOI 10.3843/GLOWM.414593

The Continuous Textbook of Women’s Medicine Series – Obstetrics Module

Common obstetric conditions

Volume Editor: Professor Sikolia Wanyonyi , Aga Khan University Hospital, Nairobi, Kenya

what is unstable presentation

Abnormal Lie/Presentation

First published: February 2021

Study Assessment Option

By completing 4 multiple-choice questions (randomly selected) after studying this chapter readers can qualify for Continuing Professional Development awards from FIGO plus a Study Completion Certificate from GLOWM See end of chapter for details

what is unstable presentation

INTRODUCTION

The mechanism of labor and delivery, as well as the safety and efficacy, is determined by the specifics of the fetal and maternal pelvic relationship at the onset of labor. Normal labor occurs when regular and painful contractions cause progressive cervical dilatation and effacement, accompanied by descent and expulsion of the fetus. Abnormal labor involves any pattern deviating from that observed in the majority of women who have a spontaneous vaginal delivery and includes:

  • Protraction disorders (slower than normal progress);
  • Arrest disorders (complete cessation of progress).

Among the causes of abnormal labor is the disproportion between the presenting part of the fetus and the maternal pelvis, which rather than being a true disparity between fetal size and maternal pelvic dimensions, is usually due to a malposition or malpresentation of the fetus.

This chapter reviews how to define, diagnose, and manage the clinical impact of abnormalities of fetal lie and malpresentation with the most commonly occurring being the breech-presenting fetus.

DEFINITIONS

At the onset of labor, the position of the fetus in relation to the birth canal is critical to the route of delivery and, thus, should be determined early. Important relationships include fetal lie, presentation, attitude, and position .

Fetal lie describes the relationship of the fetal long axis to that of the mother. In more than 99% of labors at term, the fetal lie is longitudinal . A transverse lie is less frequent when the fetal and maternal axes may cross at a 90 ° angle, and predisposing factors include multiparity, placenta previa, hydramnios, and uterine anomalies. Occasionally, the fetal and maternal axes may cross at a 45 ° angle, forming an oblique lie . 

Fetal presentation

The presenting part is the portion of the fetal body that is either foremost within the birth canal or in closest proximity to it. Thus, in longitudinal lie, the presenting part is either the fetal head or the breech, creating cephalic and breech presentations , respectively. The shoulder is the presenting part when the fetus lies with the long axis transversely.

Commonly the baby lies longitudinally with cephalic presentation. However, in some instances, a fetus may be in breech where the fetal buttocks are the presenting part. Breech fetuses are also referred to as malpresentations. Fetuses that are in a transverse lie may present the fetal back (or shoulders, as in the acromial presentation), small parts (arms and legs), or the umbilical cord (as in a funic presentation) to the pelvic inlet. When the fetal long axis is at an angle to the bony inlet, and no palpable fetal part generally is presenting, the fetus is likely in oblique lie. This lie usually is transitory and occurs during fetal conversion between other lies during labor.

The point of direction is the most dependent portion of the presenting part. In cephalic presentation in a well-flexed fetus, the occiput is the point of direction.

The fetal position refers to the location of the point of direction with reference to the four quadrants of the maternal outlet as viewed by the examiner. Thus, position may be right or left as well as anterior or posterior.

Unstable lie

Refers to the frequent changing of fetal lie and presentation in late pregnancy (usually refers to pregnancies >37 weeks).

Fetal position

Fetal position refers to the relationship of an arbitrarily chosen portion of the fetal presenting part to the right or left side of the birth canal. With each presentation there may be two positions – right or left. The fetal occiput, chin (mentum) and sacrum are the determining points in vertex, face, and breech presentations. Thus:

  • left and right occipital presentations
  • left and right mental presentations
  • left and right sacral presentations.

Fetal attitude

The fetus instinctively forms an ovoid mass that corresponds to the shape of the uterine cavity towards the third trimester, a characteristic posture described as attitude or habitus. The fetus becomes folded upon itself to create a convex back, the head is flexed, and the chin is almost in contact with the chest. The thighs are flexed over the abdomen and the legs are bent at the knees. The arms are usually parallel to the sides or lie across the chest while the umbilical cord fills the space between the extremities. This posture is as a result of fetal growth and accommodation to the uterine cavity. It is possible that the fetal head can become progressively extended from the vertex to face presentation resulting in a change of fetal attitude from convex (flexed) to concave (extended) contour of the vertebral column.

The categories of frank, complete, and incomplete breech presentations differ in their varying relations between the lower extremities and buttocks (Figure 1). With a frank breech, lower extremities are flexed at the hips and extended at the knees, and thus the feet lie close to the head. With a complete breech, both hips are flexed, and one or both knees are also flexed. With an incomplete breech, one or both hips are extended. As a result, one or both feet or knees lie below the breech, such that a foot or knee is lowermost in the birth canal. A footling breech is an incomplete breech with one or both feet below the breech.

what is unstable presentation

Types of breech presentation. Reproduced from WHO 2006, 1 with permission.

The relative incidence of differing fetal and pelvic relations varies with diagnostic and clinical approaches to care.

About 1 in 25 fetuses are breech at the onset of labor and about 1 in 100 are transverse or oblique, also referred to as non-axial. 2

With increasing gestational age, the prevalence of breech presentation decreases. In early pregnancy the fetus is highly mobile within a relatively large volume of amniotic fluid, therefore it is a common finding. The incidence of breech presentation is 20–25% of fetuses at <28 weeks, but only 7–16% at 32 weeks, and only 3–4% at term. 2 , 3

Face and brow presentation are uncommon. Their prevalence compared with other types of malpresentations are shown below. 4

  • Occiput posterior – 1/19 deliveries;
  • Breech – 1/33 deliveries;
  • Face – 1/600–1/800 deliveries;
  • Brow – 1/500–1/4000 deliveries;
  • Transverse lie – 1/833 deliveries;
  • Compound – 1/1500 deliveries.

Transverse lie is often unstable and fetuses in this lie early in pregnancy later convert to a cephalic or breech presentation.

The fetus has a relatively larger head than body during most of the late second and early third trimester, it therefore tends to spend much of its time in breech presentation or in a non-axial lie as it rotates back and forth between cephalic and breech presentations. The relatively large volume of amniotic fluid present facilitates this dynamic presentation.

Abnormal fetal lie is frequently seen in multifetal gestation, especially with the second twin. In women of grand parity, in whom relaxation of the abdominal and uterine musculature tends to occur, a transverse lie may be encountered. Prematurity and macrosomia are also predisposing factors. Distortion of the uterine cavity shape, such as that seen with leiomyomas, prior uterine surgery, or developmental anomalies (Mullerian fusion defects), predisposes to both abnormalities in fetal lie and malpresentations. The location of the placenta also plays a contributing role with fundal and cornual implantation being seen more frequently in breech presentation. Placenta previa is a well-described affiliate for both transverse lie and breech presentation.

Fetuses with congenital anomalies also present with abnormalities in either presentation or lie. It is possibly as a cause (i.e. fitting the uterine cavity optimally) or effect (the fetus with a neuromuscular condition that prevents the normal turning mechanism). The finding of an abnormal lie or malpresentation requires a thorough search for fetal abnormalities. Such abnormalities could include chromosomal (autosomal trisomy) and structural abnormalities (hydrocephalus), as well as syndromes of multiple effects (fetal alcohol syndrome).

In most cases, breech presentation appears to be as a chance occurrence; however, up to 15% may be owing to fetal, maternal, or placental abnormalities. It is commonly thought that a fetus with normal anatomy, activity, amniotic fluid volume, and placental location adopts the cephalic presentation near term because this position is the best fit for the intrauterine space, but if any of these variables is abnormal, then breech presentation is more likely.

Factors associated with breech presentation are shown in Table 1.

Risk factors for breech presentation.

Preterm gestation

Previous breech presentation in sibling or parent

Uterine abnormality (e.g., bicornuate or septate uterus, fibroid)

Placental location (e.g., placenta previa

Multiparity

Extremes of amniotic fluid volume (polyhydramnios, oligohydramnios)

Fetal anomaly (e.g., anencephaly, hydrocephaly, sacrococcygeal teratoma)

Fetal neurologic impairment

Fetal growth restriction

Maternal anticonvulsant therapy

Older maternal age

Crowding from multiple gestation

Extended fetal legs

Short umbilical cord

Contracted maternal pelvis

Female sex

Spontaneous version may occur at any time before delivery, even after 40 weeks of gestation. A prospective longitudinal study using serial ultrasound examinations reported the likelihood of spontaneous version to cephalic presentation after 36 weeks was 25%. 5

In population-based registries, the frequency of breech presentation in a second pregnancy was approximately 2% if the first pregnancy was not a breech presentation and approximately 9% if the first pregnancy was a breech presentation. After two consecutive pregnancies with breech presentation at delivery, the risk of another breech presentation was approximately 25% and this rose to 40% after three consecutive breech deliveries. 6 , 7

In addition, parents who themselves were delivered at term from breech presentation were twice as likely to have their offspring in breech presentation as parents who were delivered in cephalic presentation. This suggests a possible heritable component to fetal presentation. 8

Leopold’s maneuvers

what is unstable presentation

The Leopold’s maneuvers: palpation of fetus in left occiput anterior position. Reproduced from World Health Organization, 2006, 1   with permission.

Abdominal examination can be conducted systematically employing the four maneuvers described by Leopold in 1894. 9 , 10 In obese patients, in polyhydramnios patients or those with anterior placenta, these maneuvers are difficult to perform and interpret.

The first maneuver is to assess the uterine fundus. This allows the identification of fetal lie and determination of which fetal pole, cephalic or podalic – occupies the fundus. In breech presentation, there is a sensation of a large, nodular mass, whereas the head feels hard and round and is more mobile.

The second maneuver is accomplished as the palms are placed on either side of the maternal abdomen, and gentle but deep pressure is exerted. On one side, a hard, resistant structure is felt – the back. On the other, numerous small, irregular, mobile parts are felt – the fetal extremities. By noting whether the back is directed anteriorly, transversely, or posteriorly, fetal orientation can be determined.

The third maneuver aids confirmation of fetal presentation. The thumb and fingers of one hand grasp the lower portion of the maternal abdomen just above the symphysis pubis. If the presenting part is not engaged, a movable mass will be felt, usually the head. The differentiation between head and breech is made as in the first maneuver.

The fourth maneuver helps determine the degree of descent. The examiner faces the mother’s feet, and the fingertips of both hands are positioned on either side of the presenting part. They exert inward pressure and then slide caudad along the axis of the pelvic inlet. In many instances, when the head has descended into the pelvis, the anterior shoulder or the space created by the neck may be differentiated readily from the hard head.

According to Lyndon-Rochelle et al ., 11 experienced clinicians have accurately identified fetal malpresentation using Leopold maneuvers with a high sensitivity 88%, specificity 94%, positive-predictive value 74%, and negative-predictive value 97%.

Vaginal examination

Prelabor diagnosis of fetal presentation is difficult as the presenting part cannot be palpated through a closed cervix. Once labor begins and the cervix dilates, and palpation through vaginal examination is possible. Vertex presentations and their positions are recognized by palpation of the various fetal sutures and fontanels, while face and breech presentations are identified by palpation of facial features or the fetal sacrum and perineum, respectively.

Sonography and radiology

Sonography is the gold standard for identifying fetal presentation. This can be done during antenatal period or intrapartum. In obese women or in women with muscular abdominal walls this is especially important. Compared with digital examinations, sonography for fetal head position determination during second stage labor is more accurate. 12 , 13

COMPLICATIONS

Adverse outcomes in malpresented fetuses are multifactorial. They could be due to either underlying conditions associated with breech presentation (e.g., congenital anomalies, intrauterine growth restriction, preterm birth) or trauma during delivery.

Neonates who were breech in utero are more at risk for mild deformations (e.g., frontal bossing, prominent occiput, upward slant and low-set ears), torticollis, and developmental dysplasia of the hip.

Other obstetric complications include prolapse of the umbilical cord, intrauterine infection, maldevelopment as a result of oligohydramnios, asphyxia, and birth trauma and all are concerns.

Birth trauma especially to the head and cervical spine, is a significant risk to both term and preterm infants who present breech. In cephalic presenting fetuses, the labor process prepares the head for delivery by causing molding which helps the fetus to adapt to the birth canal. Conversely, the after-coming head of the breech fetus must descend and deliver rapidly and without significant change in shape. Therefore, small alterations in the dimensions or shape of the maternal bony pelvis or the attitude of the fetal head may have grave consequences. This process poses greater risk to the preterm infant because of the relative size of the fetal head and body. Trauma to the head is not eliminated by cesarean section; both intracranial and cervical spine trauma may result from entrapment in either the uterine or abdominal incisions.

In resource-limited countries where ultrasound imaging, urgent cesarean delivery, and neonatal intensive care are not readily available, the maternal and perinatal mortality/morbidity associated with transverse lie in labor can be high. Uterine rupture from prolonged labor in a transverse lie is a major reason for maternal/perinatal mortality and morbidity.

EXTERNAL CEPHALIC VERSION

External cephalic version (ECV) is the manual rotation of the fetus from a non-cephalic to a cephalic presentation by manipulation through the maternal abdomen (Figure 3).

what is unstable presentation

External version of breech presentation . Reproduced from WHO 2003 , 14  with  permission .

This procedure is usually performed as an elective procedure in women who are not in labor at or near term to improve their chances of having a vaginal cephalic birth. ECV reduces the risk of non-cephalic presentation at birth by approximately 60% (relative risk [RR] 0.42, 95% CI 0.29–0.61) and reduces the risk of cesarean delivery by approximately 40% (RR 0.57, 95% CI 0.40–0.82). 7

In a 2008 systematic review of 84 studies including almost 13,000 version attempts at term, the pooled success rate was 58%. 15  

A subsequent large series of 2614 ECV attempts over 18 years reported a success rate of 49% and provided more details): 16

  • The success rate was 40% in nulliparous women and 64% in parous women.
  • After successful ECV, 97% of fetuses remained cephalic at birth, 86% of which were delivered vaginally.
  • Spontaneous version to a cephalic presentation occurred after 4.3% of failed attempts, and 2.2% of successfully vertexed cases reverted to breech.

Factors associated with lower ECV success rates include nulliparity, anterior placenta, lateral or cornual placenta, decreased amniotic fluid volume, low birth weight, obesity, posteriorly located fetal spine, frank breech presentation, ruptured membranes.

The following factors should be considered while managing malpresentations: type of malpresentation, gestational age at diagnosis, availability of skilled personnel, institutional resources and protocols and patient factors and preferences.

Breech presentation

According to a term breech trial, 17 planned cesarean delivery carries a reduced perinatal mortality and early neonatal morbidity for babies with breech presentation at term compared to vaginal breech delivery. When planning a breech vaginal birth, appropriate patient selection and skilled personnel in breech delivery are key in achieving good neonatal outcomes. In appropriately selected patients and skilled personnel in vaginal breech deliveries, perinatal mortality is between 0.8 and 1.7/1000 for planned vaginal breech birth and between 0 and 0.8/1000 for planned cesarean section. 18 , 19 The choice of the route of delivery should therefore be made considering the availability of skilled personnel in conducting breech vaginal delivery; providing competent newborn care; conducting rapid cesarean delivery should need arise and performing ECV if desired; availability of resources for continuous intrapartum fetal heart rate and labor monitoring; patient clinical features, preferences and values; and institutional policies, protocols and resources.

Four approaches to the management of breech presentation are shown in Figure 4: 8

what is unstable presentation

Management of breech presentation. ECV, external cephalic version.

The options available are:

  • Attempting external cephalic version (ECV) before labor with a trial of labor if successful and conducting cesarean delivery if unsuccessful.
  • Footling or kneeling breech presentation;
  • Fetal macrosomia;
  • Fetal growth restriction;
  • Hyperextended fetal neck in labor;
  • Previous cesarean delivery;
  • Unavailability of skilled personnel in breech delivery;
  • Other contraindications to vaginal delivery like placenta previa, cord prolapse;
  • Fetal anomaly that may interfere with vaginal delivery like hydrocephalus.
  • Planned cesarean delivery without an attempt at ECV.
  • Planned trial of vaginal breech delivery in patients with favorable clinical characteristics for vaginal delivery without an attempt at ECV.

All the four approaches should be discussed in detail with the patient, and in light of all the considerations highlighted above, a safe plan of care agreed upon by both the patient and the clinician in good time.

Transverse and oblique lie

If a diagnosis of transverse/oblique fetal lie is made before onset of labor and there are no contraindications to vaginal birth or ECV, ECV can be attempted at 37 weeks' gestation. If the malpresentation recurs, further attempts at ECV can be made at 38–39 weeks with induction of labor if successful.

ECV can also be attempted in early labor with intact fetal membranes and no contraindications to vaginal birth.

If ECV is declined or is unsuccessful, then planned cesarean section should be arranged after 39 weeks' gestation.

MANAGEMENT OF LABOR AND DELIVERY

Skills to conduct vaginal breech delivery are very important as there are women who may opt for planned vaginal breech birth and even among those who choose planned cesarean delivery, about 10% may go into labor and end up with a vaginal breech delivery. 17 Some implications of cesarean delivery such as need for repeat cesarean deliveries, placental attachment disorders and uterine rupture make vaginal birth more desirable to some individuals. In addition, vaginal birth has advantages such as affordability, quicker recovery, shorter hospital stay, less complications and is more favorable for resource poor settings.

In appropriately selected women, planned vaginal breech birth is not associated with any significant long-term neurological morbidity. Regardless of planned mode of birth, cerebral palsy occurs in approximately 1.5/1,000 breech births, and abnormal neurological development occurs in approximately 3/100. 18 Careful patient selection is very important for good outcomes and it is generally agreed that women who choose to undergo a trial of labor and vaginal breech delivery should be at low risk of complications from vaginal breech delivery. Some contraindications to vaginal breech delivery have been highlighted above.

Women with breech presentation near term, pre- or early-labor ultrasound should be performed to assess type of breech presentation, flexion of the fetal head and fetal growth. If a woman presents in labor and ultrasound is unavailable and has not recently been performed, cesarean section is recommended. Vaginal breech deliveries should only take place in a facility with ability and resources readily available for emergency cesarean delivery should the need arise.

Induction of labor may be considered in carefully selected low-risk women. Augmentation of labor is controversial as poor progress of labor may be a sign of cephalo-pelvic disproportion, however, it may be considered in the event of weak contractions. A cesarean delivery should be performed if there is poor progress of labor despite adequate contractions. Labor analgesia including epidural can be used as needed.

Vaginal breech delivery should be conducted in a facility that is able to carry out continuous electronic fetal heart rate monitoring sufficient personnel to monitor the progress of labor. From the term breech trial, 17 the commonest indications for cesarean section are poor progress of labor (50%) and fetal distress (29%). There is an increased risk of cord compression which causes variable decelerations. Since the fetal head is at the fundus where contractions begin, the incidence of early decelerations arising from head compression is also higher. Due to the irregular contour of the presenting part which presents a high risk of cord prolapse, immediate vaginal examination should be undertaken if membranes rupture to rule out cord prolapse. The frequency of cord prolapse is 1% with frank breech and more than 10% in footling breech. 8

Fetal blood sampling from the buttocks is not recommended. A passive second stage of up to 90 minutes before active pushing is acceptable to allow the breech to descend well into the pelvis. Once active pushing commences, delivery should be accomplished or imminent within 60 minutes. 18

During planned vaginal breech birth, a skilled clinician experienced in vaginal breech birth should supervise the first stage of labor and be present for the active second stage of labor and delivery. Staff required for rapid cesarean section and skilled neonatal resuscitation should be in-hospital during the active second stage of labor.

The optimum maternal position in second stage has not been extensively studied. Episiotomy should be undertaken as needed and only after the fetal anus is visible at the vulva. Breech extraction of the fetus should be avoided. The baby should be allowed to deliver spontaneously with maternal effort only and without any manipulations at least until the level of the umbilicus. A loop of the cord is then pulled to avoid cord compression. After this point, suprapubic pressure can be applied to facilitate flexion of the fetal head and descent.

Delay of arm delivery can be managed by sweeping them across the face and downwards towards in front of the chest or by holding the fetus at the hips or bony pelvis and performing a 180° rotation to deliver the first arm and shoulder and then in the opposite direction so that the other arm and shoulder can be delivered i.e.,  Lovset’s maneuver (Figure 5).

what is unstable presentation

Lovset’s maneuver. Reproduced from WHO 2006 , 1  with  permission . 

The fetal head can deliver spontaneously or by the following maneuvers:

  • Turning the body to the floor with application of suprapubic pressure to flex the head and neck.

what is unstable presentation

Mauriceau-smellie-veit maneuver . Reproduced from WHO 2003, 14 with permission.

  • By use of Piper’s forceps.
  • Burns-Marshall maneuver  where the baby’s legs and trunk are allowed to hang until the nape of the neck is visible at the mother’s perineum so that its weight exerts gentle downwards and backwards traction to promote flexion of the head. The fetal trunk is then swept in a wide arc over the maternal abdomen by grasping both the feet and maintaining gentle traction; the aftercoming head is slowly born in this process.

If the above methods fail to deliver the fetal head, symphysiotomy and zavanelli maneuver with cesarean section can be attempted. Duhrssen incisions where 1–3 full length incisions are made on an incompletely dilated cervix at the 6, 2 and 10 o’clock positions can be done especially in preterm.

Face presentation

The diagnosis of face presentation is made during vaginal examination where the presenting portion of the fetus is the fetal face between the orbital ridges and the chin. At diagnosis, 60% of all face presentations are mentum anterior, 26% are mentum posterior and 15% are mentum transverse. Since the submentobregmatic (face presentation) and suboccipitobregmatic (vertex presentation) have the same diameter of 9.5 cm, most face presentations can have a successful vaginal birth and not necessarily require cesarean section delivery. 6 The position of a fetus in face presentation helps in guiding the management plan. Over 75% of mentum anterior presentations will have a successful vaginal delivery, whereas it is impossible to have a vaginal birth in mentum posterior position unless it converts spontaneously to mentum anterior position. In mentum posterior position the neck is maximally extended and cannot extend further to deliver beneath the symphysis pubis (Figure 7).

what is unstable presentation

Face presentation. Reproduced from WHO 2003, 14 with permission.

As in breech management, face presentation also requires continuous fetal heart rate monitoring, since abnormalities of fetal heart rate are more common. 5 , 6 In one study , 20 only 14% of pregnancies had normal tracings, 29% developed variable decelerations and 24% had late decelerations. Internal fetal heart rate monitoring with an electrode is not recommended, as it may cause facial and ophthalmic injuries if incorrectly placed. Labor augmentation and cesarean sections are performed as per standard obstetric indications. Vacuum and midforceps delivery should be avoided, but an outlet forceps delivery can be attempted. Attempts to manually convert the face to vertex or to rotate a posterior position to a more favorable anterior mentum position are rarely successful and are associated with high fetal morbidity and mortality, and maternal morbidity, including cord prolapse, uterine rupture, and fetal cervical spine injury with neurological impairment.

Brow presentation

The diagnosis of brow presentation is made during vaginal examination in second stage of labor where the presenting portion of the fetal head is between the orbital ridge and the anterior fontanel.

Brow presentation may be encountered early in labor, but is usually a transitional state and converts to a vertex presentation after the fetal neck flexes. Occasionally, further extension may occur resulting in a face presentation. The majority of brow presentations diagnosed early in labor convert to a more favorable presentation and deliver vaginally. Once brow presentation is confirmed, continuous fetal heart rate monitoring is necessary and labor progress should be monitored closely in order to pick any signs of abnormal labor. Since the brow diameter is large (13.5 cm), persistent brow presentation usually results in prolonged or arrested labor requiring a cesarean delivery. Labor augmentation and instrumental deliveries are therefore not recommended.

CESAREAN DELIVERY

This is an option for women with breech presentation at term to choose cesarean section as their preferred mode of delivery, for those with unsuccessful ECV who do not want to attempt vaginal breech delivery, have contraindications for vaginal breech delivery or in the event that there is no available skilled personnel to safely conduct a vaginal breech delivery. Women should be given enough and accurate information about pros and cons for both planned cesarean section and planned vaginal delivery to help them make an informed decision.

Since the publication of the term breech trial, 17 , 19 there has been a dramatic global shift from selective to planned cesarean delivery for women with breech presentation at term. This study revealed that planned cesarean section carried a reduced perinatal mortality and early neonatal morbidity for babies with breech presentation at term compared to planned vaginal birth (RR 0.33, 95% CI 0.19–0.56). The cesarean delivery rate for breech presentation is now about 70% in European countries, 95% in the United States and within 2 months of the study’s publication, there was a 50–80% increase in rates of cesarean section for breech presentation in The Netherlands.

A planned cesarean delivery should be scheduled at term between 39–41 weeks' gestation to allow maximum time for spontaneous cephalic version and minimize the risk of neonatal respiratory problems. 8 Physical exam and ultrasound should be performed immediately prior to the surgery to confirm the fetal presentation. A detailed consent should be obtained prior to surgery and should include both short- and long-term complications of cesarean section and the alternatives of care that are available. The abdominal and uterine incisions should be sufficiently large to facilitate easy delivery. Thereafter, extraction of the fetus is similar to what is detailed above for vaginal delivery.

Cesarean section for face presentation is indicated for persistent mentum posterior position, mentum transverse and some mentum anterior positions where there is standard indication for cesarean section.

Persistent brow presentation usually necessitates cesarean delivery due to the large presenting diameter that causes arrest or protracted labor.

Transverse/oblique lie

Cesarean section is indicated for patients who present in active labor, in those who decline ECV, following an unsuccessful ECV or in those with contraindications to vaginal birth.

For dorsosuperior (back up) transverse lie, a low transverse incision is made on the uterus and an attempt to grasp the fetal feet with footling breech extraction is made. If this does not succeed, a vertical incision is made to convert the hysterotomy into an inverted T incision.

Dorsoinferior (back down) transverse lie is more difficult to deliver since the fetal feet are hard to grasp. An attempt at intraabdominal version to cephalic or breech presentation can be done if membranes are intact before the uterine incision is made. Another option is to make a vertical uterine incision; however, the disadvantage of this is the risk of uterine rupture in subsequent pregnancies.

PERINATAL OUTCOME

Availability of skilled neonatal care at delivery is important for good perinatal outcomes to facilitate resuscitation if needed for all fetal malpresentations. 8 All newborns born from fetal malpresentations require a thorough examination to check for possible injuries resulting from birth or as the cause of the malpresentation.

Neonates who were in face presentation often have facial edema and bruising/ecchymosis from vaginal examinations that usually resolve within 24–48 hours of life and low Apgar scores. Trauma during labor may cause tracheal and laryngeal edema immediately after delivery, which can result in neonatal respiratory distress and difficulties in resuscitative efforts.

PRACTICE RECOMMENDATIONS

  • Diagnosis of unstable lie is made when a varying fetal lie is found on repeated clinical examination in the last month of pregnancy.
  • Consider external version to correct lie if not longitudinal.
  • Consider ultrasound to exclude mechanical cause.
  • Inform woman of need for prompt admission to hospital if membranes rupture or when labor starts.
  • If spontaneous rupture of membranes occurs, perform vaginal examination to exclude the presence of a cord or malpresentation.
  • If the lie is not longitudinal in labor and cannot be corrected perform cesarean section.

CONFLICTS OF INTEREST

Author(s) statement awaited.

Publishers’ note: We are constantly trying to update and enhance chapters in this Series. So if you have any constructive comments about this chapter please provide them to us by selecting the "Your Feedback" link in the left-hand column.

1

WHO. , 2nd edn. World Health Organization, 2006:51. Available: .

2

Scheer K, Nubar J. Variation of fetal presentation with gestational age. 1976;125(2):269–70.

3

Hickok DE, Gordon DC, Milberg JA, The frequency of breech presentation by gestational age at birth: a large population-based study. 1992;166(3):851–85

4

Sorensen T, Hasch E, Lange AP. Fetal presentation during pregnancy. 1979;2(8140):477.

5

Hughey MJ. Fetal position during pregnancy. 1985;153(8):885–6.

6

Gardberg M, Leonova Y, Laakkonen E. Malpresentations–impact on mode of delivery. 2011;90(5):540–2.

7

Ghosh MK. Breech presentation: evolution of management. 2005;50(2):108–16.

8

Hofmeyr G. Overview of breech presentation. UpToDate [Internet] Waltham, MA: UpToDate. 2014.

9

Kastner I, Kachlik D. [German gynecologist and obstetrician Christian Gerhard Leopold (1846–1911)]. 2010;75(3):218–21.

10

Sharma JB. Evaluation of Sharma's modified Leopold's maneuvers: a new method for fetal palpation in late pregnancy. 2009;279(4):481–7.

11

Lydon-Rochelle M, Albers L, Gorwoda J, Accuracy of Leopold maneuvers in screening for malpresentation: a prospective study. 1993;20(3):132–5.

12

Ramphul M, Kennelly M, Murphy DJ. Establishing the accuracy and acceptability of abdominal ultrasound to define the foetal head position in the second stage of labour: a validation study. 2012;164(1):35–9.

13

Wiafe YA, Whitehead B, Venables H, The effectiveness of intrapartum ultrasonography in assessing cervical dilatation, head station and position: A systematic review and meta-analysis. 2016;24(4):222–32.

14

WHO. . Geneva: World Health Organization, 2003. Available: .

15

Grootscholten K, Kok M, Oei SG, External cephalic version-related risks: a meta-analysis. 2008;112(5):1143–51.

16

Melo P, Georgiou EX, Hedditch A, External cephalic version at term: a cohort study of 18 years' experience. 2019;126(4):493–9.

17

Hannah ME, Hannah WJ, Hewson SA,  Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. 2000;356(9239):1375–83.

18

Kotaska A, Menticoglou S. No. 384-Management of Breech Presentation at Term. 2019;41(8):1193–205.

19

No G-tG. management of breech presentation: green-top guideline No. 20b management of breech presentation: Green-top guideline No. 20b. 2017.

20

Benedetti TJ, Lowensohn RI, Truscott A. Face presentation at term. 1980;55(2):199–202.

Online Study Assessment Option All readers who are qualified doctors or allied medical professionals can now automatically receive 2 Continuing Professional Development credits from FIGO plus a Study Completion Certificate from GLOWM for successfully answering 4 multiple choice questions (randomly selected) based on the study of this chapter. Medical students can receive the Study Completion Certificate only.

(To find out more about FIGO’s Continuing Professional Development awards programme CLICK HERE )

I wish to proceed with Study Assessment for this chapter

We use cookies to ensure you get the best experience from our website. By using the website or clicking OK we will assume you are happy to receive all cookies from us.

what is unstable presentation

Unstable Angina Clinical Presentation

  • Author: Walter Tan, MD, MS; Chief Editor: Eric H Yang, MD  more...
  • Sections Unstable Angina
  • Practice Essentials
  • Pathophysiology
  • Epidemiology
  • Patient Education
  • Physical Examination
  • Braunwald Classification
  • Canadian Cardiovascular Society Grading System
  • Acute Coronary Syndrome Risk Assessment
  • Risk Stratification: TIMI and GRACE Risk Scores
  • Approach Considerations
  • Basic Blood Studies
  • Cardiac Biomarkers
  • Electrocardiography
  • Echocardiography
  • SPECT and MRI
  • Myocardial Perfusion Imaging
  • Exercise Testing
  • Initial Medical Management
  • Role of Medical Therapy With Anticoagulation
  • Further Medical Management
  • Cardiac Catheterization
  • Revascularization
  • Consultations
  • 2023 ESC Guidelines for the Management of ACS
  • 2020 ESC Acute Coronary Syndromes Clinical Practice Guidelines
  • 2014 AHA/ACC and 2015 ESC Guidelines for the Management NSTE-ACS
  • Medication Summary
  • Antiplatelet agents
  • Lipid-Lowering Agents, Statins
  • PCSK9 Inhibitors
  • Antiplatelet Agent, Cardiovascular
  • Beta-Blockers, Beta-1 Selective
  • Beta-Blockers, Beta-1 Selective; Antidysrhythmics, II
  • Beta-Blockers, Nonselective
  • Beta-Blockers, Nonselective; Antidysrhythmics, II
  • Anticoagulant
  • Low Molecular Weight Heparins
  • ACE Inhibitors
  • Thrombin inhibitors
  • Nitrates, Angina
  • Questions & Answers
  • Media Gallery

Patients with unstable angina represent a heterogeneous population. Therefore, the clinician must obtain a focused history of the patient’s symptoms and coronary risk factors and immediately review the electrocardiogram (ECG) to develop an early risk stratification. (See Prognosis .)

Initially, obtain a history to determine whether any evidence of angina is present, then aim to identify whether it is stable or unstable.

Unstable angina differs from stable angina in that the discomfort is usually more intense and easily provoked, and ST-segment depression or elevation on ECG may occur. Otherwise, the manifestations of unstable angina are similar to those of other conditions of myocardial ischemia, such as chronic stable angina and myocardial infarction (MI). With unstable angina, symptoms may (1) occur at rest; (2) become more frequent, severe, or prolonged than the usual pattern of angina; (3) change from the usual pattern of angina; or (4) not respond to rest or nitroglycerin. [ 3 ]

Angina can take many forms, and inquiry should be directed at eliciting not only chest pain but also any associated discomfort and its frequency, location, radiation pattern, and precipitating and alleviating factors.

Ischemic pain can manifest as heaviness, tightness, aching, fullness, or burning of the chest, epigastrium, or arm or forearm (usually the left). These sensations less typically involve the back, lower jaw, neck, shoulders, or arms. Important associated symptoms may be dyspnea, generalized fatigue, diaphoresis, nausea and vomiting, flulike symptoms, and, less commonly, lightheadedness or abdominal pain. The intensity of pain on a 1-10 scale does not correlate with diagnosis or prognosis.

Elderly and female patients are more likely to present with atypical signs and symptoms.

The physical examination is usually not as sensitive or specific for unstable angina as the history or diagnostic tests. An unremarkable physical examination is not uncommon. Perform a quick assessment of patients’ vital signs, and perform a cardiac examination. Specific diagnoses that must be explicitly considered are the following:

Aortic dissection

Leaking or ruptured thoracic aneurysm

Pericarditis with tamponade

Pulmonary embolism

Pneumothorax

Peptic ulcer disease

Increased autonomic activity may manifest as diaphoresis or tachycardia, and bradycardia may result from vagal stimulation from inferior wall myocardial ischemia.

A large area of myocardial jeopardy may manifest as signs of transient myocardial dysfunction and typically signifies a higher-risk situation. Such signs include the following:

Systolic blood pressure less than 100 mm Hg or overt hypotension

Elevated jugular venous pressure

Dyskinetic apex

Reverse splitting of the second heart sound

Presence of a third or fourth heart sound

New or worsening apical systolic murmur due to papillary muscle dysfunction

Rales or crackles

Findings indicative of peripheral arterial occlusive disease or prior stroke increase the likelihood of associated coronary artery disease (CAD) and are as follows:

Carotid bruit

Supraclavicular or femoral bruits

Diminished peripheral pulses or blood pressure

Any sign of congestive heart failure (CHF), including isolated sinus tachycardia, particularly in physiologically vulnerable populations (eg, very elderly patients), should trigger expeditious workup, treatment, or consultation with a cardiologist. Such patients can deteriorate rapidly.

The number and diversity of clinical conditions that cause the transient myocardial ischemia of unstable angina, along with its varying intensity and frequency of pain, have made classification within this disorder difficult.

The Braunwald classification (see Table 4 below) is conceptually useful, in that it factors in the clinical presentation (new or progressive vs rest angina), context (primary, secondary, or post-MI), and intensity of antianginal therapy.

Table 4. Braunwald Classification of Unstable Angina (Open Table in a new window)

Severity

I

Symptoms with exertion

II

Subacute symptoms at rest (2-30 days prior)

III

Acute symptoms at rest (within prior 48 hr)

Clinical precipitating factor

A

Secondary

B

Primary

C

Postinfarction

Therapy during symptoms

1

No treatment

2

Usual angina therapy

3

Maximal therapy

Patients in Braunwald class I have new or accelerated exertional angina, whereas those in class II have subacute (>48 hours since last pain) or class III acute (< 48 hours since last pain) rest angina. The clinical circumstances associated with unstable angina are categorized as follows:

Secondary (anemia, fever, hypoxia)

Postinfarction (< 2 weeks after MI)

Intensity of antianginal therapy is subclassified as follows:

No treatment

Usual oral therapy

Intense therapy (eg, intravenous [IV] nitroglycerin)

Because of its simplicity and practicality, the Canadian Cardiovascular Society Grading System for effort-related angina is widely used to describe symptom severity. The grading system is as follows:

Grade I: Angina with strenuous, rapid, or prolonged exertion; ordinary physical activity, such as climbing stairs, does not provoke angina

Grade II: Slight limitation of ordinary activity; angina occurs with postprandial, uphill, or rapid walking; when walking more than two blocks of level ground or climbing more than one flight of stairs; during emotional stress; or in the early hours after awakening

Grade III: Marked limitation of ordinary activity; angina occurs with walking 1-2 blocks or climbing a flight of stairs at a normal pace

Grade IV: Inability to carry on any physical activity without discomfort; rest pain occurs

Estimation of the likelihood of acute coronary syndrome (ACS) is a complex, multivariable problem that cannot be fully specified in the list below, which is meant more to illustrate major relations than to offer rigid algorithms. A high likelihood of ACS includes any of the following features:

History of previous MI, sudden death, or other known history of CAD

Chest, neck, jaw, or left arm pain consistent with prior documented angina

Transient hemodynamic or ECG changes during pain

ST-segment elevation or depression of 1 mm or more

Marked symmetrical T-wave inversion in multiple precordial leads

An intermediate likelihood of ACS includes the absence of high-likelihood features but the presence of one of the following risk characteristics:

Age greater than 70 years

Diabetes mellitus

Extracardiac vascular disease (peripheral, brachiocephalic, or renal artery atherosclerosis)

ST depression of 0.05-1 mm

T-wave inversion of 1 mm or greater in leads with dominant R waves

A low likelihood of ACS includes the absence of high- or intermediate-likelihood features and the presence of any of the following:

Chest pain classified as probably not angina

Chest discomfort reproduced by palpation

T-wave flattening or inversion of less than 1 mm in leads with dominant R waves

Normal ECG findings

The risk of adverse events in patients should be quantified. However, similar to weather predictions, there is a “cone of uncertainty” to the many models that have attempted this risk quantification through the years. Hence, a prediction model will never exist that can forecast definite danger or definite safety. One reason for this is many factors remain that are either unmeasured, unmeasurable, or unknown. [ 23 ] Moreover, these factors are not constantly updated to account for demographic shifts or advances in preventive therapies. Nonetheless, among a number of models with overlapping variables, the Thrombolysis in Myocardial Infarction (TIMI) and (updated) Global Registry of Acute Coronary Events (GRACE) risk models have had a reasonable performance and are also updated. [ 24 , 25 ]

TIMI risk score

The TIMI risk score for unstable angina/non-ST elevation MI (UA/NSTEMI) is currently the best-validated, simple (7-item) prognostic instrument that can be hand calculated in settings such as an urgent care center or emergency department. The risk gradient of MI, severe recurrent ischemia, or death is somewhat proportionate to the TIMI risk score (see the image below), talhough an adverse prognosis may be mitigated by the use of newer antithrombotic strategies and the current lower rates of smoking or other risk factors.

Unstable Angina. Thrombolysis in Myocardial Infarc

The presence of any of the following variables constitutes 1 point, with the sum constituting the patient risk score on a scale of 0-7:

Age 65 years or older

Three or more coronary artery disease (CAD) risk factors (hypertension, hypercholesterolemia, diabetes, family history or CAD, or current smoker)

Known coronary stenosis of 50% or greater

Use of aspirin in the preceding 7 days

ECG ST deviation/changes larger than 0.5 mm

  • Positive cardiac markers

GRACE risk score

The GRACE risk score is recommended in international guidelines for the risk stratification of non-ST-elevation acute coronary syndrome (NSTE-ACS). Although the GRACE risk score is a more complicated calculation, fortunately, it is readily available online here . An analysis from University of Michigan that compared the GRACE risk score to the simpler and more convenient TIMI risk score showed a similar prediction of 6-month mortality in STEMI patients, but there was superior discrimination with the GRACE risk score in the UA/NSTEMI population for in-hospital (concordance statistic [C] = 0.85 vs 0.54, respectively) and 6-month (C = 0.79 vs 0.56, respectively) mortality. [ 26 ]

Basra SS, Virani SS, Paniagua D, Kar B, Jneid H. Acute coronary syndromes: unstable angina and non-ST elevation myocardial infarction. Heart Fail Clin . 2016 Jan. 12(1):31-48. [QxMD MEDLINE Link] .

Hedayati T, Yadav N, Khanagavi J. Non-ST-segment acute coronary syndromes. Cardiol Clin . 2018 Feb. 36(1):37-52. [QxMD MEDLINE Link] .

Cunha JP. What is angina (ischemic chest pain)?. eMedicineHealth. August 6, 2021. Available at https://www.emedicinehealth.com/angina_pectoris/article_em.htm . Accessed: January 19, 2022.

Stone GW, Maehara A, Lansky AJ, et al. A prospective natural-history study of coronary atherosclerosis. N Engl J Med . 2011 Jan 20. 364(3):226-35. [QxMD MEDLINE Link] . [Full Text] .

Harrap SB, Zammit KS, Wong ZY, et al. Genome-wide linkage analysis of the acute coronary syndrome suggests a locus on chromosome 2. Arterioscler Thromb Vasc Biol . 2002 May 1. 22(5):874-8. [QxMD MEDLINE Link] . [Full Text] .

Zhao YH, Xu Y, Gu YY, Li Y, Zhang JY, Su X. Functional effect of platelet membrane glycoprotein ia gene polymorphism in the pathogenesis of unstable angina pectoris. J Int Med Res . 2011. 39(2):541-8. [QxMD MEDLINE Link] . [Full Text] .

Fiotti N, Moretti ME, Bussani R, et al. Features of vulnerable plaques and clinical outcome of UA/NSTEMI: Relationship with matrix metalloproteinase functional polymorphisms. Atherosclerosis . 2011 Mar. 215(1):153-9. [QxMD MEDLINE Link] .

White AJ, Duffy SJ, Walton AS, et al. Matrix metalloproteinase-3 and coronary remodelling: implications for unstable coronary disease. Cardiovasc Res . 2007 Sep 1. 75(4):813-20. [QxMD MEDLINE Link] .

Manzoli A, Andreotti F, Varlotta C, et al. Allelic polymorphism of the interleukin-1 receptor antagonist gene in patients with acute or stable presentation of ischemic heart disease. Cardiologia . 1999 Sep. 44(9):825-30. [QxMD MEDLINE Link] .

Tziakas DN, Chalikias GK, Antonoglou CO, et al. Apolipoprotein E genotype and circulating interleukin-10 levels in patients with stable and unstable coronary artery disease. J Am Coll Cardiol . 2006 Dec 19. 48(12):2471-81. [QxMD MEDLINE Link] . [Full Text] .

Willerson JT. Systemic and local inflammation in patients with unstable atherosclerotic plaques. Prog Cardiovasc Dis . 2002 May-Jun. 44(6):469-78. [QxMD MEDLINE Link] .

Scirica BM, Moliterno DJ, Every NR, et al. Differences between men and women in the management of unstable angina pectoris (The GUARANTEE Registry). The GUARANTEE Investigators. Am J Cardiol . 1999 Nov 15. 84(10):1145-50. [QxMD MEDLINE Link] .

Skolnick AH, Alexander KP, Chen AY, et al. Characteristics, management, and outcomes of 5,557 patients age > or =90 years with acute coronary syndromes: results from the CRUSADE Initiative. J Am Coll Cardiol . 2007 May 1. 49(17):1790-7. [QxMD MEDLINE Link] . [Full Text] .

Hoekstra JW, Pollack CV Jr, Roe MT, et al. Improving the care of patients with non-ST-elevation acute coronary syndromes in the emergency department: the CRUSADE initiative. Acad Emerg Med . 2002 Nov. 9(11):1146-55. [QxMD MEDLINE Link] . [Full Text] .

Organisation to Assess Strategies for Ischemic Syndromes (OASIS-2) Investigators. Effects of recombinant hirudin (lepirudin) compared with heparin on death, myocardial infarction, refractory angina, and revascularisation procedures in patients with acute myocardial ischaemia without ST elevation: a randomised trial. Lancet . 1999 Feb 6. 353(9151):429-38. [QxMD MEDLINE Link] .

Luepker RV. WHO MONICA project: What have we learned and where to go from here?. Public Health Rev. 2012 . 2011 Dec 12. 33(2):373-96. [Full Text] .

Center for Outcomes Research. GRACE, Global Registry of Acute Coronary Events. University of Massachusetts Medical School. Available at https://www.outcomes-umassmed.org/grace/ . Accessed: September 16, 2010.

Puelacher C, Gugala M, Adamson PD, et al. Incidence and outcomes of unstable angina compared with non-ST-elevation myocardial infarction. Heart . 2019 Sep. 105(18):1423-31. [QxMD MEDLINE Link] .

Cannon CP, McCabe CH, Stone PH, et al, for the TIMI III Registry ECG Ancillary Study Investigators. The electrocardiogram predicts one-year outcome of patients with unstable angina and non-Q wave myocardial infarction: results of the TIMI III Registry ECG Ancillary Study. Thrombolysis in Myocardial Ischemia. J Am Coll Cardiol . 1997 Jul. 30(1):133-40. [QxMD MEDLINE Link] . [Full Text] .

Lupon J, Valle V, Marrugat J, et al, for the for the RESCATE Investigators. Six-month outcome in unstable angina patients without previous myocardial infarction according to the use of tertiary cardiologic resources. J Am Coll Cardiol . 1999 Dec. 34(7):1947-53. [QxMD MEDLINE Link] . [Full Text] .

Wallentin L, Becker RC, Budaj A, et al. Ticagrelor versus clopidogrel in patients with acute coronary syndromes. N Engl J Med . 2009 Sep 10. 361(11):1045-57. [QxMD MEDLINE Link] . [Full Text] .

Tanindi A, Erkan AF, Ekici B. Epicardial adipose tissue thickness can be used to predict major adverse cardiac events. Coron Artery Dis . 2015 Dec. 26 (8):686-91. [QxMD MEDLINE Link] .

Bai XF, Zhang YP, Zhou J, et al. Combination of the CYP2C19 metabolizer and the GRACE risk score better predicts the long-term major adverse cardiac events in acute coronary syndrome undergoing percutaneous coronary intervention. Thromb Res . 2018 Oct. 170:142-7. [QxMD MEDLINE Link] . [Full Text] .

Chen CW, Hsieh YC, Hsieh MH, Lin YK, Huang CY, Yeh JS. Predictive power of in-hospital and long-term mortality of the GRACE, TIMI, revised CADILLAC and PAMI score in NSTEMI patients with diabetes - data from TSOC ACS-DM registry. Acta Cardiol Sin . 2020 Nov. 36(6):595-602. [QxMD MEDLINE Link] . [Full Text] .

Huang W, FitzGerald G, Goldberg RJ, et al, for the TRACE-CORE Investigators. Performance of the GRACE Risk Score 2.0 simplified algorithm for predicting 1-year death after hospitalization for an acute coronary syndrome in a contemporary multiracial cohort. Am J Cardiol . 2016 Oct 15. 118(8):1105-10. [QxMD MEDLINE Link] . [Full Text] .

Aragam KG, Tamhane UU, Kline-Rogers E, et al. Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores. PLoS One . 2009 Nov 23. 4(11):e7947. [QxMD MEDLINE Link] . [Full Text] .

Karcz A, Holbrook J, Burke MC, et al. Massachusetts emergency medicine closed malpractice claims: 1988-1990. Ann Emerg Med . 1993 Mar. 22(3):553-9. [QxMD MEDLINE Link] .

Li Z, Liu X, Wang J, et al. Analysis of urinary metabolomic profiling for unstable angina pectoris disease based on nuclear magnetic resonance spectroscopy. Mol Biosyst . 2015 Dec 10. 11(12):3387-96. [QxMD MEDLINE Link] .

Gurses KM, Kocyigit D, Yalcin MU, et al. Enhanced platelet toll-like receptor 2 and 4 expression in acute coronary syndrome and stable angina pectoris. Am J Cardiol . 2015 Dec 1. 116(11):1666-71. [QxMD MEDLINE Link] .

Meune C, Balmelli C, Twerenbold R, et al. Patients with acute coronary syndrome and normal high-sensitivity troponin. Am J Med . 2011 Dec. 124(12):1151-7. [QxMD MEDLINE Link] .

Susilovic Grabovac Z, Bakovic D, Lozo M, Pintaric I, Dujic Z. Early changes in platelet size and number in patients with acute coronary syndrome. Int J Angiol . 2017 Dec. 26(4):249-52. [QxMD MEDLINE Link] . [Full Text] .

Misra D, Leibowitz K, Gowda RM, Shapiro M, Khan IA. Role of N-acetylcysteine in prevention of contrast-induced nephropathy after cardiovascular procedures: a meta-analysis. Clin Cardiol . 2004 Nov. 27(11):607-10. [QxMD MEDLINE Link] . [Full Text] .

Calmarza P, Lapresta C, Martinez M, Lahoz R, Povar J. Utility of myeloperoxidase in the differential diagnosis of acute coronary syndrome. Arch Cardiol Mex . 2018 Dec. 88(5):391-6. [QxMD MEDLINE Link] .

Than M, Cullen L, Reid CM, et al. A 2-h diagnostic protocol to assess patients with chest pain symptoms in the Asia-Pacific region (ASPECT): a prospective observational validation study. Lancet . 2011 Mar 26. 377(9771):1077-84. [QxMD MEDLINE Link] .

Thygesen K, Alpert JS, Jaffe AS, et al. Third universal definition of myocardial infarction. Eur Heart J . 2012 Oct. 33(20):2551-67. [QxMD MEDLINE Link] . [Full Text] .

Januzzi JL, Cannon CP, DiBattiste PM, Murphy S, Weintraub W, Braunwald E. Effects of renal insufficiency on early invasive management in patients with acute coronary syndromes (The TACTICS-TIMI 18 Trial). Am J Cardiol . 2002 Dec 1. 90(11):1246-9. [QxMD MEDLINE Link] .

Acara AC, Bolatkale M. Endothelial nitric oxide level as a predictor of coronary complexity in patients with unstable angina pectoris. Am J Med Sci . 2019 Jun. 357(6):453-60. [QxMD MEDLINE Link] .

[Guideline] Kervinen H. Acute coronary syndrome and myocardial infarction. EBM Guidelines. Evidence-Based Medicine [internet] . Helsinki: Duodecim Medical Publications Ltd; 2018 Oct 20. [Full Text] .

[Guideline] Gulati M, Levy PD, Mukherjee D, et al. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation . 2021 Nov 30. 144 (22):e368-e454. [QxMD MEDLINE Link] . [Full Text] .

de Zwaan C, Bär FW, Wellens HJ. Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction. Am Heart J . 1982 Apr. 103(4 pt 2):730-6. [QxMD MEDLINE Link] .

Nisbet BC, Zlupko G. Repeat Wellens' syndrome: case report of critical proximal left anterior descending artery restenosis. J Emerg Med . 2010 Sep. 39(3):305-8. [QxMD MEDLINE Link] .

Kwong RY, Chan AK, Brown KA, et al. Impact of unrecognized myocardial scar detected by cardiac magnetic resonance imaging on event-free survival in patients presenting with signs or symptoms of coronary artery disease. Circulation . 2006 Jun 13. 113(23):2733-43. [QxMD MEDLINE Link] . [Full Text] .

Kwong RY, Sattar H, Wu H, et al. Incidence and prognostic implication of unrecognized myocardial scar characterized by cardiac magnetic resonance in diabetic patients without clinical evidence of myocardial infarction. Circulation . 2008 Sep 2. 118(10):1011-20. [QxMD MEDLINE Link] . [Full Text] .

Stratmann HG, Younis LT, Wittry MD, Amato M, Miller DD. Exercise technetium-99m myocardial tomography for the risk stratification of men with medically treated unstable angina pectoris. Am J Cardiol . 1995 Aug 1. 76(4):236-40. [QxMD MEDLINE Link] .

Udelson JE, Spiegler EJ. Emergency department perfusion imaging for suspected coronary artery disease: the ERASE Chest Pain Trial. Md Med . 2001 Spring. Suppl:90-4. [QxMD MEDLINE Link] .

Tegn N, Abdelnoor M, Aaberge L, et al, for the After Eighty study investigators. Health-related quality of life in older patients with acute coronary syndrome randomised to an invasive or conservative strategy. The After Eighty randomised controlled trial. Age Ageing . 2018 Jan 1. 47(1):42-7. [QxMD MEDLINE Link] .

[Guideline] Collet JP, Thiele H, Barbato E, et al, for the ESC Scientific Document Group . 2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. Eur Heart J . 2021 Apr 7. 42(14):1289-367. [QxMD MEDLINE Link] . [Full Text] .

[Guideline] Lawton JS, Tamis-Holland JE, Bangalore S, et al. 2021 ACC/AHA/SCAI Guideline for coronary artery revascularization: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation . 2022 Jan 18. 145(3):e18-e114. [QxMD MEDLINE Link] . [Full Text] .

[Guideline] Amsterdam EA, Wenger NK, Brindis RG, et all, for the ACC/AHA Task Force Members. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation . 2014 Dec 23. 130(25):e344-426. [QxMD MEDLINE Link] . [Full Text] .

Yusuf S, Zhao F, Mehta SR, Chrolavicius S, Tognoni G, Fox KK. Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation. N Engl J Med . 2001 Aug 16. 345(7):494-502. [QxMD MEDLINE Link] . [Full Text] .

Beavers CJ, Naqvi IA. Clopidogrel. StatPearls [Internet] . 2022 Jan. [QxMD MEDLINE Link] . [Full Text] .

Peters RJ, Mehta SR, Fox KA, et al. Effects of aspirin dose when used alone or in combination with clopidogrel in patients with acute coronary syndromes: observations from the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) study. Circulation . 2003 Oct 7. 108(14):1682-7. [QxMD MEDLINE Link] .

Steinhubl SR, Berger PB, Mann JT 3rd, et al. Early and sustained dual oral antiplatelet therapy following percutaneous coronary intervention: a randomized controlled trial. JAMA . 2002 Nov 20. 288(19):2411-20. [QxMD MEDLINE Link] .

Mega JL, Close SL, Wiviott SD, et al. Cytochrome p-450 polymorphisms and response to clopidogrel. N Engl J Med . 2009 Jan 22. 360(4):354-62. [QxMD MEDLINE Link] . [Full Text] .

Pare G, Mehta SR, Yusuf S, et al. Effects of CYP2C19 genotype on outcomes of clopidogrel treatment. N Engl J Med . 2010 Oct 28. 363(18):1704-14. [QxMD MEDLINE Link] . [Full Text] .

Park KW, Kim HS. Options to overcome clopidogrel response variability. Circ J . 2012. 76(2):287-92. [QxMD MEDLINE Link] .

O'Connor FF, Shields DC, Fitzgerald A, Cannon CP, Braunwald E, Fitzgerald DJ. Genetic variation in glycoprotein IIb/IIIa (GPIIb/IIIa) as a determinant of the responses to an oral GPIIb/IIIa antagonist in patients with unstable coronary syndromes. Blood . 2001 Dec 1. 98(12):3256-60. [QxMD MEDLINE Link] . [Full Text] .

De Servi S, Goedicke J, Schirmer A, Widimsky P. Clinical outcomes for prasugrel versus clopidogrel in patients with unstable angina or non-ST-elevation myocardial infarction: an analysis from the TRITON-TIMI 38 trial. Eur Heart J Acute Cardiovasc Care . 2014 Dec. 3(4):363-72. [QxMD MEDLINE Link] .

Rudolph TK, Fuchs A, Klinke A, et al. Prasugrel as opposed to clopidogrel improves endothelial nitric oxide bioavailability and reduces platelet-leukocyte interaction in patients with unstable angina pectoris: A randomized controlled trial. Int J Cardiol . 2017 Dec 1. 248:7-13. [QxMD MEDLINE Link] .

Effron MB, Nair KV, Molife C, et al. One-year clinical effectiveness comparison of prasugrel with ticagrelor: results from a retrospective observational study using an integrated claims database. Am J Cardiovasc Drugs . 2018 Apr. 18(2):129-41. [QxMD MEDLINE Link] .

US FDA approves expanded indication for BRILINTA to include long-term use in patients with a history of heart attack [press release]. AstraZeneca. September 3, 2015. Available at https://www.astrazeneca.com/Media/Press-releases/Article/20150903 . Accessed: September 9, 2015.

Bonaca MP, Bhatt DL, Cohen M, et al, for the PEGASUS-TIMI 54 Steering Committee and Investigators. Long-term use of ticagrelor in patients with prior myocardial infarction. N Engl J Med . 2015 May 7. 372(19):1791-800. [QxMD MEDLINE Link] . [Full Text] .

Simoons ML. Effect of glycoprotein IIb/IIIa receptor blocker abciximab on outcome in patients with acute coronary syndromes without early coronary revascularisation: the GUSTO IV-ACS randomised trial. Lancet . 2001 Jun 16. 357(9272):1915-24. [QxMD MEDLINE Link] .

Ibbotson T, McGavin JK, Goa KL. Abciximab: an updated review of its therapeutic use in patients with ischaemic heart disease undergoing percutaneous coronary revascularisation. Drugs . 2003. 63(11):1121-63. [QxMD MEDLINE Link] .

Roffi M, Chew DP, Mukherjee D, et al. Platelet glycoprotein IIb/IIIa inhibitors reduce mortality in diabetic patients with non-ST-segment-elevation acute coronary syndromes. Circulation . 2001 Dec 4. 104(23):2767-71. [QxMD MEDLINE Link] . [Full Text] .

Branch KR, Probstfield JL, Eikelboom JW, et al. Rivaroxaban with or without aspirin in patients with heart failure and chronic coronary or peripheral artery disease. Circulation . 2019 Aug 13. 140(7):529-37. [QxMD MEDLINE Link] . [Full Text] .

Korjian S, Braunwald E, Daaboul Y, et al. Usefulness of rivaroxaban for secondary prevention of acute coronary syndrome in patients with history of congestive heart failure (from the ATLAS-ACS-2 TIMI-51 Trial). Am J Cardiol . 2018 Dec 1. 122(11):1896-901. [QxMD MEDLINE Link] . [Full Text] .

[Guideline] Knuuti J, Wijns W, Saraste A, et al, for the ESC Scientific Document Group. 2019 ESC Guidelines for the diagnosis and management of chronic coronary syndromes. Eur Heart J . 2020 Jan 14. 41(3):407-77. [QxMD MEDLINE Link] . [Full Text] .

Marquis-Gravel G, Goodman SG, Anderson TJ, et al. Colchicine for prevention of atherothrombotic events in patients with coronary artery disease: review and practical approach for clinicians. Can J Cardiol . 2021 Nov. 37(11):1837-45. [QxMD MEDLINE Link] .

Andrade-Castellanos CA, Colunga-Lozano LE, Delgado-Figueroa N, Magee K. Heparin versus placebo for non-ST elevation acute coronary syndromes. Cochrane Database Syst Rev . 2014 Jun 27. 6:CD003462. [QxMD MEDLINE Link] . [Full Text] .

Cohen M, Demers C, Gurfinkel EP, et al. Low-molecular-weight heparins in non-ST-segment elevation ischemia: the ESSENCE trial. Efficacy and safety of subcutaneous enoxaparin versus intravenous unfractionated heparin, in non-Q-wave coronary events. Am J Cardiol . 1998 Sep 10. 82(5B):19L-24L. [QxMD MEDLINE Link] .

Ferguson JJ, Califf RM, Antman EM, et al. Enoxaparin vs unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndromes managed with an intended early invasive strategy: primary results of the SYNERGY randomized trial. JAMA . 2004 Jul 7. 292(1):45-54. [QxMD MEDLINE Link] .

Mehta SR, Granger CB, Eikelboom JW, et al. Efficacy and safety of fondaparinux versus enoxaparin in patients with acute coronary syndromes undergoing percutaneous coronary intervention: results from the OASIS-5 trial. J Am Coll Cardiol . 2007 Oct 30. 50(18):1742-51. [QxMD MEDLINE Link] . [Full Text] .

Theroux P, Waters D, Lam J, Juneau M, McCans J. Reactivation of unstable angina after the discontinuation of heparin. N Engl J Med . 1992 Jul 16. 327(3):141-5. [QxMD MEDLINE Link] . [Full Text] .

Direct Thrombin Inhibitor Trialists' Collaborative Group. Direct thrombin inhibitors in acute coronary syndromes: principal results of a meta-analysis based on individual patients' data. Lancet . 2002 Jan 26. 359(9303):294-302. [QxMD MEDLINE Link] .

Metz BK, White HD, Granger CB, et al. Randomized comparison of direct thrombin inhibition versus heparin in conjunction with fibrinolytic therapy for acute myocardial infarction: results from the GUSTO-IIb Trial. Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO-IIb) Investigators. J Am Coll Cardiol . 1998 Jun. 31(7):1493-8. [QxMD MEDLINE Link] . [Full Text] .

Maroo A, Lincoff AM. Bivalirudin in PCI: an overview of the REPLACE-2 trial. Semin Thromb Hemost . 2004 Jun. 30(3):329-36. [QxMD MEDLINE Link] .

Stone GW, McLaurin BT, Cox DA, et al. Bivalirudin for patients with acute coronary syndromes. N Engl J Med . 2006 Nov 23. 355(21):2203-16. [QxMD MEDLINE Link] . [Full Text] .

Schwartz GG, Olsson AG, Ezekowitz MD, et al. Effects of atorvastatin on early recurrent ischemic events in acute coronary syndromes: the MIRACL study: a randomized controlled trial. JAMA . 2001 Apr 4. 285(13):1711-8. [QxMD MEDLINE Link] .

Murphy SA, Cannon CP, Wiviott SD, McCabe CH, Braunwald E. Reduction in recurrent cardiovascular events with intensive lipid-lowering statin therapy compared with moderate lipid-lowering statin therapy after acute coronary syndromes from the PROVE IT-TIMI 22 (Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction 22) trial. J Am Coll Cardiol . 2009 Dec 15. 54(25):2358-62. [QxMD MEDLINE Link] .

US Food and Drug Administration. Safety: Zocor (simvastatin): label change - new restrictions, contraindications, and dose limitations. Available at https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-new-restrictions-contraindications-and-dose-limitations-zocor . June 8, 2011; Accessed: June 5, 2013.

US Food and Drug Administration. FDA Drug Safety Communication: Important safety label changes to cholesterol-lowering statin drugs. Available at https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-important-safety-label-changes-cholesterol-lowering-statin-drugs . February 28, 2012; Accessed: June 5, 2013.

US Food & Drug Administration. FDA Drug Safety Communication: Interactions between certain HIV or hepatitis C drugs and cholesterol-lowering statin drugs can increase the risk of muscle injury. Available at https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-interactions-between-certain-hiv-or-hepatitis-c-drugs-and-cholesterol . March 1, 2012; Accessed: June 5, 2013.

Soukoulis V, Boden WE, Smith SC Jr, O'Gara PT. Nonantithrombotic medical options in acute coronary syndromes: old agents and new lines on the horizon. Circ Res . 2014 Jun 6. 114(12):1944-58. [QxMD MEDLINE Link] . [Full Text] .

Anderson HV, Cannon CP, Stone PH, et al. One-year results of the Thrombolysis in Myocardial Infarction (TIMI) IIIB clinical trial. A randomized comparison of tissue-type plasminogen activator versus placebo and early invasive versus early conservative strategies in unstable angina and non-Q wave myocardial infarction. J Am Coll Cardiol . 1995 Dec. 26(7):1643-50. [QxMD MEDLINE Link] . [Full Text] .

Boden WE, O'Rourke RA, Crawford MH, et al, for the Veterans Affairs Non–Q-Wave Infarction Strategies in Hospital (VANQWISH) Trial Investigators. Outcomes in patients with acute non-Q-wave myocardial infarction randomly assigned to an invasive as compared with a conservative management strategy. Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) Trial Investigators. N Engl J Med . 1998 Jun 18. 338(25):1785-92. [QxMD MEDLINE Link] . [Full Text] .

Invasive compared with non-invasive treatment in unstable coronary-artery disease: FRISC II prospective randomised multicentre study. FRagmin and Fast Revascularisation during InStability in Coronary artery disease Investigators. Lancet . 1999 Aug 28. 354(9180):708-15. [QxMD MEDLINE Link] .

Fox KA, Poole-Wilson PA, Henderson RA, et al. Interventional versus conservative treatment for patients with unstable angina or non-ST-elevation myocardial infarction: the British Heart Foundation RITA 3 randomised trial. Randomized Intervention Trial of unstable Angina. Lancet . 2002 Sep 7. 360(9335):743-51. [QxMD MEDLINE Link] .

Damman P, Hirsch A, Windhausen F, Tijssen JG, de Winter RJ. 5-year clinical outcomes in the ICTUS (Invasive versus Conservative Treatment in Unstable coronary Syndromes) trial a randomized comparison of an early invasive versus selective invasive management in patients with non-ST-segment elevation acute coronary syndrome. J Am Coll Cardiol . 2010 Mar 2. 55(9):858-64. [QxMD MEDLINE Link] . [Full Text] .

Neumann FJ, Kastrati A, Pogatsa-Murray G, et al. Evaluation of prolonged antithrombotic pretreatment ("cooling-off" strategy) before intervention in patients with unstable coronary syndromes: a randomized controlled trial. JAMA . 2003 Sep 24. 290(12):1593-9. [QxMD MEDLINE Link] .

Wallentin L, Lagerqvist B, Husted S, Kontny F, Stale E, Swahn E. Outcome at 1 year after an invasive compared with a non-invasive strategy in unstable coronary-artery disease: the FRISC II invasive randomised trial. FRISC II Investigators. Fast Revascularisation during Instability in Coronary artery disease. Lancet . 2000 Jul 1. 356(9223):9-16. [QxMD MEDLINE Link] .

Sabatine MS, Giugliano RP, Keech AC, et al, for the FOURIER Steering Committee and Investigators. Evolocumab and clinical outcomes in patients with cardiovascular disease. N Engl J Med . 2017 May 4. 376(18):1713-22. [QxMD MEDLINE Link] . [Full Text] .

Szarek M, White HD, Schwartz GG, et al, for the ODYSSEY OUTCOMES Committees and Investigators. Alirocumab reduces total nonfatal cardiovascular and fatal events: The ODYSSEY OUTCOMES Trial. J Am Coll Cardiol . 2019 Feb 5. 73(4):387-96. [QxMD MEDLINE Link] . [Full Text] .

[Guideline] American Diabetes Association. Standards of Medical Care in Diabetes-2016 abridged for primary care providers. Clin Diabetes . 2016 Jan. 34(1):3-21. [QxMD MEDLINE Link] . [Full Text] .

[Guideline] Byrne RA, Rossello X, Coughlan JJ, et al, for ESC Scientific Document Group. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J Acute Cardiovasc Care . 2024 Feb 9. 13 (1):55-161. [QxMD MEDLINE Link] . [Full Text] .

Zoler ML. ESC’s revised NSTE-ACS guidelines embrace hsT, personalized anti-ischemia treatments. Medscape Medical News. September 1, 2020. Available at https://www.medscape.com/viewarticle/936676 . Accessed: September 28, 2020.

[Guideline] Roffi M, Patrono C, Collet JP, et al, for the ESC Scientific Document Group. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J . 2016 Jan 14. 37(3):267-315. [QxMD MEDLINE Link] . [Full Text] .

[Guideline] Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA Guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines: An Update of the 2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention, 2011 ACCF/AHA Guideline for Coronary Artery Bypass Graft Surgery, 2012 ACC/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Isc... Circulation . 2016 Sep 6. 134(10):e123-55. [QxMD MEDLINE Link] . [Full Text] .

Amgen Inc. FDA approves Amgen's Repatha (evolocumab) to prevent heart attack and stroke. December 1, 2017. Available at https://www.amgen.com/media/news-releases/2017/12/fda-approves-amgens-repatha-evolocumab-to-prevent-heart-attack-and-stroke/ . Accessed: December 5, 2017.

Sanofi-Aventis. FDA approves Praluent (alirocumab) to prevent heart attack, stroke and unstable angina requiring hospitalization [press release]. April 26, 2019. Available at https://www.news.sanofi.us/2019-04-26-FDA-approves-Praluent-R-alirocumab-to-prevent-heart-attack-stroke-and-unstable-angina-requiring-hospitalization . Accessed: April 30, 2019.

US Food and Drug Administration. Safety: Meridia (sibutramine): market withdrawal due to risk of serious cardiovascular events. Available at https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm228830.htm . October 8, 2010; Accessed: June 5, 2013.

Busko M. New non-ST-elevation ACS guidelines: new title, new approach. Medscape Medical News from WebMD. September 29, 2014. Available at https://www.medscape.com/viewarticle/832513 . Accessed: October 4, 2014.

Eggers KM, Jernberg T, Lindahl B. Unstable angina in the era of cardiac troponin assays with improved sensitivity-a clinical dilemma. Am J Med . 2017 Dec. 130(12):1423-30.e5. [QxMD MEDLINE Link] .

Nowak R, Mueller C, Giannitsis E, et al. High sensitivity cardiac troponin T in patients not having an acute coronary syndrome: results from the TRAPID-AMI study. Biomarkers . 2017 Dec. 22(8):709-14. [QxMD MEDLINE Link] .

Rottger E, de Vries-Spithoven S, Reitsma JB, et al. Safety of a 1-hour rule-out high-sensitive troponin T protocol in patients with chest pain at the emergency department. Crit Pathw Cardiol . 2017 Dec. 16(4):129-34. [QxMD MEDLINE Link] .

Driscoll A, Barnes EH, Blankenberg S, et al. Predictors of incident heart failure in patients after an acute coronary syndrome: The LIPID heart failure risk-prediction model. Int J Cardiol . 2017 Dec 1. 248:361-8. [QxMD MEDLINE Link] .

  • Unstable Angina. Pathogenesis of acute coronary syndromes.
  • Unstable Angina. Thrombolysis in Myocardial Infarction (TIMI) Risk Score correlates with major adverse outcome and effect of therapy with low-molecular-weight heparin. ARD = absolute risk difference; ESSENCE = Efficacy and Safety of Subcutaneous Enoxaparin in Non–Q-wave Coronary Events; No. = number; NNT = number needed to treat.
  • Unstable Angina. Algorithm for initial invasive strategy. ASA = acetylsalicylic acid (aspirin); GP IIb/IIIa= glycoprotein IIb/IIIa; IV = intravenous; LOE = level of evidence; UA/NSTEMI = unstable angina/non–ST-segment elevation myocardial infarction; UFH = unfractionated heparin. (Adapted from 2007 ACC/AHA UA/NSTEMI Guidelines.)
  • Unstable Angina. Algorithm for initial conservative strategy. ASA = acetylsalicylic acid (aspirin); EF = ejection fraction; GP IIb/IIIa= glycoprotein IIb/IIIa; IV = intravenous; LOE = level of evidence; LVEF = left ventricular ejection fraction; UA/NSTEMI = unstable angina/non–ST-segment elevation myocardial infarction. (Adapted from 2007 ACC/AHA UA/NSTEMI Guidelines.)
  • Unstable Angina. Rate and timing of revascularization for patients with unstable angina using invasive versus conservative approach (FRagmin during InStability in Coronary artery disease [FRISC] II).
  • Unstable Angina. Time course of elevations of serum markers after acute myocardial infarction. CK = creatine kinase; CK-MB = creatine kinase MB fraction; LDH = lactate dehydrogenase.
  • Table 1. Patient Characteristics, GUARANTEE Versus CRUSADE Trials
  • Table 2. Demographic Characteristics of Patients in International OASIS-2 Registry
  • Table 3. Thirty-Day Clinical Outcome in Patients With Acute Coronary Syndromes in Clinical Trials
  • Table 4. Braunwald Classification of Unstable Angina
  • Table 5. Recommendations for Selection of Preferred Management Strategy

]

]

Mean age (y)

62

69

Patients >65 y (%)

44

Female (%)

39

40

Hypertension (%)

60

73

Diabetes mellitus (%)

26

33

Current smoker (%)

25

Hypercholesterolemia (%)

43

50

Previous stroke (%)

9

Previous MI (%)

36

30

Previous angina (%)

66

CHF (%)

14

18

Previous coronary intervention (%)

23

21

Previous coronary bypass surgery (%)

25

19

CHF = congestive heart failure; CRUSADE = Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the American College of Cardiology/American Heart Association guidelines; GUARANTEE = Global Unstable Angina Registry and Treatment Evaluation; MI = myocardial infarction.

]

General

Number of patients

1899

1478

1626

931

1135

918

Mean age (y)

65

62

66

65

63

66

Women (%)

37

42

37

45

40

37

Clinical

NQMI presentation (%)

7

7

14

22

17

16

Abnormal ECG (%)

74

91

82

95

97

87

Select treatments

Beta blocker (%)

67

53

73

67

59

57

Calcium blocker (%)

59

51

53

52

43

59

Invasive procedures (index hospitalization)

Cardiac catheterization (%)

24

69

43

20

7

58

PCI (%)

7

19

16

5

0.4

24

CABG (%)

4

20

10

7

0.4

17

CABG = coronary artery bypass grafting; ECG = electrocardiographic; NQMI = non-Q wave myocardial infarction; OASIS = Organization to Assess Strategies for Ischemic Syndromes; PCI = percutaneous coronary intervention.

TIMI-3

1994

1,473

2.5

9.0

0.3

GUSTO-IIb

1997

8,011

3.8

6.0

1.0

ESSENCE

1998

3,171

3.3

4.5

1.1

PARAGON-A

1998

2,282

3.2

10.3

4.0

PRISM

1998

3,232

3.0

4.2

0.4

PRISM-PLUS

1998

1,915

4.4

8.1

1.1

PURSUIT

1998

10,948

3.6

12.9

2.1

TIMI-11B

1999

3,910

3.9

6.0

1.3

PARAGON-B

2000

5,225

3.1

9.3

1.1

40,167

3.5

8.5

1.5

ESSENCE = Efficacy and Safety of Subcutaneous Enoxaparin in Non–Q-wave Coronary Events; GUSTO-IIb = Global Utilization of Streptokinase and TPA (tissue plasminogen activator) for Occluded Coronary Arteries; PARAGON-A = Platelet IIb/IIIa Antagonism (lamifiban) for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network; PARAGON-B = Platelet IIb/IIIa Antagonism (lamifiban) for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network; PRISM = Platelet Receptor Inhibition in Ischemic Syndrome Management; PRISM-PLUS = Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Angina Signs and Symptoms; PURSUIT = Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy; TIMI-11B = Thrombolysis in Myocardial Infarction Clinical Trial 11B; TIMI-3 = Thrombolysis in Myocardial Infarction Clinical Trial 3.

Severity

I

Symptoms with exertion

II

Subacute symptoms at rest (2-30 days prior)

III

Acute symptoms at rest (within prior 48 hr)

Clinical precipitating factor

A

Secondary

B

Primary

C

Postinfarction

Therapy during symptoms

1

No treatment

2

Usual angina therapy

3

Maximal therapy

Immediate Invasive Strategy

(< 2 hours)

Refractory angina
Signs/symptoms of heart failure or new or worsening mitral regurgitation
Hemodynamic instability or cardiogenic shock
Recurrent angina/ischemia at rest or with low-level activities despite intensive medical therapy
Sustained ventricular tachycardia or ventricular fibrillation
Ischemia-Guided Strategy Low-risk score (eg, TIMI 0 or 1, GRACE < 109)
Low-risk Tn-negative female
Patient or physician preference in the absence of high-risk features

Early Invasive Strategy

(< 24 hours)

GRACE score >140
Rise or fall in Tn compatible with myocardial infarction
New or presumably new ST-segment depression

Delayed Invasive Strategy

(24-72 hours)

Diabetes mellitus
Renal insufficiency (GFR < 60 mL/min/1.73m )
Reduced LV systolic function (LVEF < 40%)
Early postinfarction angina
PCI within 6 months
Prior CABG
GRACE score 109-140; TIMI Score ≥2
ACC/AHA = American College of Cardiology/American Heart Association; CABG = coronary artery bypass grafting; GFR = glomerular filtration rate; GRACE = Global Registry of Acute Coronary Events; LV = left ventricle; LVEF = left ventricular ejection fraction; PCI = percutaneous coronary intervention; TIMI = Thrombolysis in Myocardial Infarction Clinical Trial; Tn = troponin.

Previous

Contributor Information and Disclosures

Walter Tan, MD, MS Associate Professor of Medicine, Wake Forest University School of Medicine; Director of Cardiac Cath Labs, Wake Forest Baptist Medical Center Walter Tan, MD, MS is a member of the following medical societies: American Association for the Advancement of Science , American College of Cardiology , American Heart Association , American Stroke Association , National Stroke Association , Society for Vascular Medicine , Society of Interventional Radiology Disclosure: Nothing to disclose.

Frederic Ross Kahl, MD, FACC, FAHA Professor of Medicine, Cardiology Section, Department of Medicine, Professor, Department of Radiology, Professor, Translational Science Institute, Design, Epidemiology, Biostatistics, and Clinical Research Ethics Program, Associate Physician, Department of Radiology, Wake Forest University School of Medicine Frederic Ross Kahl, MD, FACC, FAHA is a member of the following medical societies: American College of Cardiology , American College of Physicians-American Society of Internal Medicine , American Heart Association , American Medical Association , Forsyth-Stokes-Davie County Medical Society, North Carolina Medical Society Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference Disclosure: Nothing to disclose.

Richard A Lange, MD, MBA President, Texas Tech University Health Sciences Center, Dean, Paul L Foster School of Medicine Richard A Lange, MD, MBA is a member of the following medical societies: Alpha Omega Alpha , American College of Cardiology , American Heart Association , Association of Subspecialty Professors Disclosure: Nothing to disclose.

Eric H Yang, MD Associate Professor of Medicine, Director of Cardiac Catherization Laboratory and Interventional Cardiology, Mayo Clinic ArizonA Eric H Yang, MD is a member of the following medical societies: Alpha Omega Alpha Disclosure: Nothing to disclose.

David J Moliterno, MD Professor of Medicine, Jefferson Morris Gill Professor of Cardiology, Chief, Division of Cardiovascular Medicine, University of Kentucky; Vice Chairman of Internal Medicine, Chandler Medical Center; Medical Director, Gill Heart Institute David J Moliterno, MD is a member of the following medical societies: American College of Cardiology , European Society of Cardiology , Association of Professors of Cardiology , American College of Physicians , American Heart Association , American Medical Association Disclosure: Nothing to disclose.

Steven James Filby, MD Fellow in Interventional Cardiology, The Cleveland Clinic Foundation

Disclosure: Nothing to disclose.

Justin D Pearlman, MD, ME, PhD, FACC, MA Chief, Division of Cardiology, Director of Cardiology Consultative Service, Director of Cardiology Clinic Service, Director of Cardiology Non-Invasive Laboratory, Director of Cardiology Quality Program KMC, Dartmouth-Hitchcock Medical Center, Dartmouth Medical School

Justin D Pearlman, MD, ME, PhD, FACC, MA is a member of the following medical societies: American College of Cardiology , American College of Physicians , American Federation for Medical Research , International Society for Magnetic Resonance in Medicine , and Radiological Society of North America

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

What would you like to print?

  • Print this section
  • Print the entire contents of
  • Print the entire contents of article

Medscape Logo

  • Angina Pectoris
  • Angina Pectoris in Emergency Medicine
  • Braunwald Classification of Unstable Angina
  • Canadian Cardiovascular Society Grading System for Stable Angina
  • Abdominal Angina
  • Unstable Angina
  • Angina Bullosa Hemorrhagica
  • Coronary Sinus Reducer an Option for Intractable Angina?
  • In Angina, Gene Therapy Coaxes Heart Vessel Growth
  • PCI Benefit in Angina Clarified in New ORBITA-2 Analysis
  • Cardiac Emergencies News & Perspectives

Aug 16, 2024 This Week in Cardiology Podcast

  • Drug Interaction Checker
  • Pill Identifier
  • Calculators

ss_tako_thumb

  • 2002150215-overviewDiseases & Conditions Diseases & Conditions Angina Pectoris

Special Topics in Cardiology

  • 2002761889-overviewDiseases & Conditions Diseases & Conditions Angina Pectoris in Emergency Medicine

Abdominal Angina

IMAGES

  1. How To End A Presentation

    what is unstable presentation

  2. 10 Powerful Examples Of How To End A Presentation

    what is unstable presentation

  3. PPT

    what is unstable presentation

  4. PPT

    what is unstable presentation

  5. PPT

    what is unstable presentation

  6. Instable vs Unstable: When To Use Each One? What To Consider

    what is unstable presentation

VIDEO

  1. Unstable lie

  2. Unstable Meaning

  3. Ludochrono

  4. Unstable Presentation in Ultrasound| Unstable Lie Presentation in USG in hindi|DrDaljeet Singh Yadav

  5. The equilibrium of a rigid body and its stability

  6. Xen VGA Passthrough to Windows 8 Consumer Preview HVM Virtual Machine with Xen 4.2-unstable Demo

COMMENTS

  1. Abnormal Fetal lie, Malpresentation and Malposition

    Lie - the relationship between the long axis of the fetus and the mother. Presentation - the fetal part that first enters the maternal pelvis. Position - the position of the fetal head as it exits the birth canal. Other positions include occipito-posterior and occipito-transverse. Note: Breech presentation is the most common ...

  2. Fetal Presentation, Position, and Lie (Including Breech Presentation)

    Fetal presentation: Fetal part that overlies the maternal pelvic inlet; vertex (cephalic), face, brow, breech, shoulder, funic (umbilical cord), or compound (more than one part, eg, shoulder and hand) Fetal position: Relation of the presenting part to an anatomic axis; for vertex presentation, occiput anterior, occiput posterior, occiput transverse

  3. PDF Malpresentations, Malpositions, and Multiple Gestation

    udinal, transverse, or oblique (also called unstable). Presentation is the portion of the fetu. that is foremost, or present-ing, in the birth canal. The fetus. ay present by vertex, breech, face, brow, or shoulder. Position is a reference point on the pres. nting part and how it relates to the woman's pelvis. For exa.

  4. Fetal Presentation, Position, and Lie (Including Breech Presentation)

    In face presentation, the baby's neck arches back so that the face presents first rather than the top of the head.. In brow presentation, the neck is moderately arched so that the brow presents first.. Usually, fetuses do not stay in a face or brow presentation. These presentations often change to a vertex (top of the head) presentation before or during labor.

  5. Abnormal Fetal Lie and Presentation

    Fetal presentation is a reference to the part of the fetus that is overlying the maternal pelvic inlet. The most common relationship between fetus and mother is the longitudinal lie, cephalic presentation. A breech fetus also is a longitudinal lie, with the fetal buttocks as the presenting part.

  6. What is malpresentation?

    What are presentation and malpresentation? 'Presentation' describes how your baby is facing down the birth canal. The 'presenting part' is the part of your baby's body that is against the cervix. The ideal presentation is head-first, with the crown (top) of the baby's head against the cervix, with the chin tucked into the baby's ...

  7. Malpresentations and Malpositions Information

    Breech presentation is the most common malpresentation, with the majority discovered before labour. ... Szaboova R, Sankaran S, Harding K, et al; PLD.23 Management of transverse and unstable lie at term. Arch Dis Child Fetal Neonatal Ed. 2014 Jun;99 Suppl 1:A112-3. doi: 10.1136/archdischild-2014-306576.324.

  8. Malpresentations

    The reported incidence of face presentation ranges from 0.14% to 0.54% and averages about 0.2%, or 1 in 500 live births overall. The reported perinatal mortality rate, corrected for nonviable malformations and extreme prematurity, varies from 0.6% to 5% and averages about 2% to 3%. FIG 17-6.

  9. Fetal presentation: Breech, posterior, transverse lie, and more

    Fetal presentation, or how your baby is situated in your womb at birth, is determined by the body part that's positioned to come out first, and it can affect the way you deliver. At the time of delivery, 97 percent of babies are head-down (cephalic presentation). But there are several other possibilities, including feet or bottom first (breech ...

  10. PDF Management of an Unstable Lie at Term

    An unstable lie is the term given to a fetus that continues to change its position and does not maintain a longitudinal lie at term (≥ 37 weeks). ... A fetus that does not maintain a cephalic presentation and longitudinal lie at term may reduce the possibility of a normal vaginal delivery. Women with an unstable lie or

  11. When a Person Is Told They Have an Unstable Lie

    Both a head up (breech) and a head-down (cephalic) baby are in a vertical lie. When a baby is lying across the abdomen or sideways, we say baby is in a " Transverse lie ". An oblique lie is when baby's body is diagonal in the womb. The head or pelvis is towards one hip and the opposite "pole" or end of the baby is under the opposite rib.

  12. Management of malposition and malpresentation in labour

    Face: face presentation, encountered in 1 in 500 births, occurs when there is complete extension of the fetal head. In this presentation the denominator is the chin, for example mento-anterior or mento-posterior. The presenting diameter in this presentation is the submento-bregmatic and is the same as a flexed vertex; approximately 9.5 cm.

  13. Abnormal Lie/Presentation

    In cephalic presentation in a well-flexed fetus, the occiput is the point of direction. The fetal position refers to the location of the point of direction with reference to the four quadrants of the maternal outlet as viewed by the examiner. Thus, position may be right or left as well as anterior or posterior. Unstable lie

  14. Management of unstable and non-longitudinal lie at term in contemporary

    We have observed that there is significant variation in practice and a lack of published evidence on the management of unstable/transverse/oblique lie at term in the modern obstetric practice. The RCOG Green-top Guideline No.50 recommends elective admission after 37 + 0 weeks gestation and immediate admission with signs of labour or rupture of membranes (SROM) to reduce risk of cord prolapse [1].

  15. Transverse fetal lie

    Presentation refers to the fetal part that directly overlies the pelvic inlet; it is usually cephalic [head] or breech [buttocks] but can be a shoulder, compound [eg, head and hand], or funic [umbilical cord]. Position is the relationship of a nominated site of the presenting part to a denominating location on the maternal pelvis [eg, right ...

  16. Oblique Lie: Causes, Risks, Avoiding a Cesarean, and More

    An oblique lie is a fetal position in which baby's head is just to the side of the pelvic inlet. It presents some challenges, but there are ways to get your baby into the proper position for birth.

  17. Cephalic Position: Understanding Your Baby's Presentation at Birth

    Cephalic occiput anterior. Your baby is head down and facing your back. Almost 95 percent of babies in the head-first position face this way. This position is considered to be the best for ...

  18. PDF Focus on Clinical Presentation (00177519)

    The documentation should state "evolving clinical presentation with changing characteristics" and describe what has been changing and what will be monitored, such as fluctuating pain, swelling, changes in vital signs, etc., to support an "evolving" clinical presentation statement. UNSTABLE and unpredictable characteristics are evident ...

  19. Unstable Angina Clinical Presentation

    Unstable angina differs from stable angina in that the discomfort is usually more intense and easily provoked, and ST-segment depression or elevation on ECG may occur. Otherwise, the manifestations of unstable angina are similar to those of other conditions of myocardial ischemia, such as chronic stable angina and myocardial infarction (MI).

  20. Unstable Angina

    Unstable angina, one of several acute coronary syndromes, causes unexpected chest pain, and usually occurs while resting.The most common cause is reduced blood flow to the heart muscle because the coronary arteries are narrowed by fatty buildups (atherosclerosis) that can rupture, causing injury to the coronary blood vessel.This results in blood clotting, which blocks blood flow to the heart ...