The breech baby
USUALLY, right before birth, most babies will turn inside the womb into the ideal birth position, which is head down, to get ready for birth. In approximately four per cent of all pregnancies, which is about three to four babies per hundred, Obstetrician-gynaecologist Dr Leo Walker says that this does not happen, and the baby remains breech.
“A breech presentation describes when a foetus’ presenting part is the buttocks and/or feet. Even though the majority of breech foetuses are normal, the breech presentation has been associated with some structural abnormalities with the foetus, including developmental problems of the hips,” Dr Walker said.
He pointed out that in early pregnancy the breech presentation is a common occurrence since the foetus is highly mobile within a large volume of amniotic fluid. However, as gestational age advances, the chances of breech presentation diminish.
“Therefore, majority of foetuses will turn prior to delivery. But for those foetuses that remain in breech presentation up to 36 weeks of pregnancy, the chance that the foetus will spontaneously turn is only around six per cent,” Dr Walker explained.
There are numerous reasons why a baby may present as breech. Dr Walker said that among the risk factors for breech presentation identified are preterm pregnancies, multi-foetal pregnancies (twins, triplets), excess or reduced amniotic fluid (poly/oligohydramnios), a low lying placenta, large uterine fibroids, or a short umbilical cord.
He noted that breech presentations are usually discovered during clinical examination during routine antenatal clinic appointments, but the diagnosis is most suitably confirmed by means of an ultrasound. He said that a breech presentation can be any one of three types, with the most common presentation being the Frank breech.
“In the Frank Breech presentation, the buttocks of the foetus is the presenting part. In the Complete Breech presentation, both the hips and knees of the foetus are flexed and as such, the buttocks and feet are the presenting parts. In the Incomplete Breech presentation, however, the hips and knees a partially extended and so only the feet are presenting parts,” Dr Walker explained.
He underscored that a significant part of managing a breech presentation is knowing the exact type of breech presentation. This, he explained, will provide the appropriate guidance for a specialist to navigate the delivery.
“This concept is important because the cervix will often only dilate to accommodate the size of the presenting part. As a result, if the baby is in the incomplete breech presentation, the cervix will only dilate to the diameter of the feet, therefore resulting in a difficult delivery or even entrapment of the after-coming head,” Dr Walker said.
“If rupture of the membranes occurs, this incomplete breech presentation also increases the risk of umbilical cord prolapse, which results in an abrupt reduction in oxygen delivery to the foetus and will likely result in mortality if not delivered immediately.”
If the scans show that your baby is breech, then your doctor or midwife will explain your options to increase your chances of having a safe delivery. Even as most women prefer a vaginal delivery because of the reduced risk in comparison to surgery in normal pregnancies, Dr Walker said that in general, this might not be ideal for breech presentations.
“There is broad consensus that breech vaginal delivery increases the risk of asphyxia to the foetus and traumatic injury to both the mother and offspring. To minimise these complications, patients are often counselled regarding alternative delivery options. These generally include turning the foetus, otherwise known as external cephalic version, or an elective caesarean section (C-section),” Dr Walker advised.
While some women may opt for the external cephalic version as a way of avoiding the C-section, Dr Walker said that the procedure is not without risks.
“During the process of attempting to turn the foetus, the membranes can rupture, cord prolapse can occur, the placenta can prematurely separate (placental abruption), the patient can go into pre-term labour, and even uterine rupture can occur,” Dr Walker explained.
For this reason, he said that external cephalic version should only be done in centres where continuous monitoring of the foetal heart rate can occur and with immediate access to the operating theatre to ensure that in the event of any complications and there is a need for surgery, the woman has immediate access to the facilities.
Dr Leo Walker is a Maternal Foetal Fellow at the University Hospital. His obstetrician and gynaecology practices are located at the Westminster and Oxford Medical Centres.
