Written by:

Dr Emily Cornish

Dr Cornish is an academic Obstetrics & Gynaecology trainee in London. She recently returned from a year spent working in South Africa and is looking forward to developing her interests in maternofetal medicine, fertility and high-risk obstetrics.

External cephalic version (ECV) for breech babies

In this article:

  • Breech presentation
  • What is ECV?
  • How likely is it to be successful?
  • What are the risks of ECV?
  • What are the alternatives?
  • Main Points
  • References

External cephalic version (ECV) for breech babies

Breech presentation

Breech means that your baby is in a bottom-down position inside the womb, rather than the more common head-down (cephalic) position. During early pregnancy, while your baby has plenty of space to move, breech is very common. As pregnancy advances towards the time of birth, the majority of babies will turn into a cephalic position to facilitate a normal vaginal birth, but 3-4% of babies will remain breech at full term (37+ weeks).

A breech baby born vaginally has a slightly increased risk of problems during birth because there may be a delay in delivery of the head and then some compression of the umbilical cord as the head passes through the birth canal[1]. This increases the likelihood of requiring an episiotomy, to create extra space for the baby’s head[2].

In 2000, a large research study called the Term Breech Trial studied 2,083 mothers with breech babies and concluded that planned Caesarean was safer for the baby than vaginal breech delivery[3]. Since then, mothers with breech babies have been offered either external cephalic version (ECV) or planned Caesarean. Six years later, the results of the trial were re-analysed, and it was found that serious flaws in the design of the study meant that its recommendations were invalid[4]. However, by this point, vaginal breech delivery had become a rare occurrence and staff were no longer trained or experienced in safe vaginal breech delivery. ECV or planned Caesarean therefore remain the mainstays of management for breech babies.

What is ECV?

ECV stands for “external cephalic version”. It is a procedure used to try to rotate a breech baby to a cephalic position (i.e. from bottom-down to head-down position), increasing the mother’s chance of a straightforward vaginal delivery and reducing her risk of requiring a Caesarean. It is usually performed at around 36-38 weeks, but can also be considered later on.

Before the procedure, you may be given some medication to relax the muscles of the uterus, which can improve the chances of success and carries no risk to the baby. An experienced obstetrician will use an ultrasound scanner to determine the exact position of the baby and the location of the placenta. The obstetrician will then apply gentle pressure to your abdomen to attempt to dislodge the baby’s bottom from the pelvis and rotate it in a somersault movement. The baby’s heartbeat will be monitored before and after the procedure to detect any signs of distress.

How likely is it to be successful?

The overall success rate of ECV is approximately 50%[5], but there may be some variation according to the expertise of the person performing the procedure, how far advanced you are in your pregnancy and whether you have been pregnant before. It is more likely to be successful in women who have had a baby before (60%) than women in their first pregnancy (40%)[5].

What are the risks of ECV?

Overall, ECV is a safe procedure, and although some mothers find it uncomfortable, it has very few complications. However, there are some important considerations:

RiskFurther Information
Failure to turn the babyIf the ECV is unsuccessful on the first attempt, it is reasonable to attempt it again, up to a total of 4 times during a maximum of 10 minutes[5]. If still unsuccessful, the obstetrician will discuss alternatives with you and make an updated plan for delivery.
Emergency Caesarean sectionAbout 1 in 200 women will require a Caesarean section within 24 hours of ECV, which is usually due to either vaginal bleeding or signs of fetal distress on the baby’s heart trace. ECV will only be performed where the necessary staff and facilities for an emergency Caesarean are available[5].
Reversion to breech presentationAfter a successful ECV, only 3% of babies will spontaneously revert to breech presentation[6].
Increased risk of interventionsEven when ECV has been successful, once the mother goes into labour, there is a slightly higher risk of requiring an emergency Caesarean section or an instrumental delivery than for a mother whose baby has always been cephalic [7].

ECV should not be performed in certain circumstances[5]:

  • Recent vaginal bleeding
  • Abnormalities on the baby’s heart trace during pre-procedure monitoring
  • Previous Caesarean
  • Placenta praevia (where the placenta covers the cervix, or neck of the womb)
  • Multiple pregnancy (twins or triplets)
  • Oligohydramnios (where the amount of fluid around the baby is reduced)
  • Where the womb is an unusual shape (e.g. bicornuate, or heart-shaped, uterus)

Rhesus-negative mothers should be offered anti-D within 72 hours of ECV and should then be screened for feto-maternal haemorrhage (i.e. mixing of the baby’s and the mother’s blood, which can cause a dangerous immune reaction) using a blood test called the Kleihauer test[5].

What are the alternatives?

There are 4 alternatives:

  1. Elective Caesarean section
  2. Vaginal breech delivery
  3. Moxibustion
  4. Postural management

The steps, risks and benefits of elective Caesarean section are discussed in a separate article. If you select this option, the obstetrician doing the Caesarean will do an ultrasound scan on the day of the operation to confirm that the baby is still breech.

If a mother is keen to attempt vaginal breech delivery, she should be fully counselled on the risks, and the decision should be taken in conjunction with a senior obstetrician.

Moxibustion is a traditional Chinese medicine treatment that involves applying dried mugwort herb to particular parts of the body. The potential mechanism of action is unknown, but it is thought to increase the baby’s activity. Moxibustion has been used for several decades in China, where it is often combined with acupuncture, and it appears to be a safe and straightforward procedure. One study of 406 women who had breech babies at 33-35 weeks demonstrated a significantly higher rate of cephalic presentation at term, but there are not enough data available to recommend this as a reliable alternative to ECV[8].

There is no evidence that postural management (i.e. lying or sitting in certain positions to try to encourage the baby to turn) increases the chance of achieving a cephalic presentation[5].

Main Points

  • The majority of babies will turn into a head-down position (cephalic) before birth, but some will remain in a feet-down position (breech presentation).
  • Because there is a higher risk of complications if a breech baby is born vaginally, mothers with breech babies are offered a caesarean section or external cephalic version (ECV)
  • ECV is a procedure used to turn a breech baby into cephalic position.
  • ECV is usually performed at around 36-38 weeks, but can be offered later.
  • Before ECV, you may have medication to relax the muscles of the uterus.
  • During ECV, an obstetrician will apply gentle pressure to your abdomen to try to rotate your baby into a head-down position.
  • The success rate of ECV is approximately 50%. There is a higher chance of success in women who’ve had a baby before than women in their first pregnancy.
  • A small proportion of women (about 1 in 200) will require a caesarean section within 24 hours of ECV due to vaginal bleeding or signs of fetal distress on the baby’s heart trace.
  • In cases where ECV is successful, there is still a small chance (3%) that the baby will revert to breech presentation.
  • Even in instances where ECV is successful, the mother is at higher risk of needing a caesarean section or instrumental delivery than a mother whose baby has always been cephalic.
  • ECV can be attempted up to 4 times during a maximum of 10 minutes. If each attempt is unsuccessful, your obstetrician will discuss further options with you.
  • There are some circumstances, such as if there has been recent vaginal bleeding or abnormalities found on the baby’s heart trace, under which ECV should not be performed as the risk of complications is too high.
  • The alternatives are elective caesarean delivery, vaginal breech delivery, moxibustion, and postural management.

References

  1. Hutton EK, Hofmeyr GJ and Dowswell T, External cephalic version for breech presentation before term. Cochrane Database Syst Rev 7:CD000084 (2015)
  2. Räisänen S, Vehvilänen-Julkunen K, Gisler M and Heinonen S, A population-based register study to determine indications for episiotomy in Finland. Int J Gynaecol Obstet 115:26 (2011)
  3. Hannah ME et al., Planned Caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Term Breech Trial Collaborative Group. Lancet 356:1375 (2000)
  4. Glezerman M, Five years to the term breech trial: the rise and fall of a randomised controlled trial. Am J Obstet Gynecol 194:20 (2006)
  5. Impey LWM, Murphy DJ, Griffiths M and Penna LK on behalf of the Royal College of Obstetricians and Gynaecologists, External Cephalic Version and Reducing the Incidence of Term Breech Presentation. BJOG 124:e178 (2017)
  6. Collins S, Ellaway P, Harrington D, Pandit M and Impey LW, The complications of external cephalic version: results from 805 consecutive attempts. BJOG 114:636 (2007)
  7. Kabiri D et al., Timing of delivery after external cephalic version and the risk for cesarean delivery. Obstet Gynecol 118:209 (2011)
  8. Vas J et al., Using moxibustion in primary healthcare to correct non-vertex presentation: a multicentre randomised controlled trial. Acupunct Med 31:31 (2013)