If you find your baby is in a breech position at 36 weeks, you will be offered an ECV to turn the baby into a head-down position. Here we discuss what it involves and what your alternatives are.
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, when 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 an external cephalic version (ECV) so that they can have a cephalic vaginal delivery or a 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.
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 procedure can feel uncomfortable due to the pressure being applied on your bump, but it shouldn’t be painful. The baby’s heartbeat will be monitored before and after the procedure to detect any signs of distress.
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].
Overall, ECV is a safe procedure, and although some mothers find it uncomfortable, it has very few complications. However, there are some important considerations:
| Risk | Further Information |
|---|---|
| Failure to turn the baby | If 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 section | About 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 presentation | After a successful ECV, only 3% of babies will spontaneously revert to breech presentation[6]. |
| Increased risk of interventions | Even 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]:
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].
There are 4 alternatives:
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 is 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].