Most babies are born headfirst, but at the end of pregnancy, around 3% to 4% are found to be breech. Before 37 weeks of pregnancy, breech presentation is much more common - about 20% of babies at 28 weeks are breech, and 15% at 32 weeks.
Before term, which is defined as 37 weeks, it doesn't matter if the baby is breech, as there is always a good chance that she will turn spontaneously. Some babies do turn by themselves after this time, but it is much less likely, and some preparations should be made to decide how delivery is going to take place. About 10% to 15% of breech babies are discovered for the first time late in labour!
Before 37 weeks, the only time that it does matter if the baby is breech is if labour begins. There are many factors that will be taken into account before advising on how to have your baby if this happens.
Frequently, a caesarean section will be advised, particularly if your baby is between 27 and 30 weeks, but this is not always the case. Some obstetricians feel very strongly that a caesarean is always safer, others advise a vaginal delivery if there are no other problems.
It is generally accepted that the studies which have tried to find the safest delivery for the baby have been subject to much bias. The problems babies have when they are born early are very much related to prematurity, rather than the type of birth.
Unfortunately, it is unlikely that an adequate study to discover the best type of delivery for a premature breech baby will ever be done.
If a planned early delivery is needed, for example because of preeclampsia, growth problems or another separate problem of pregnancy, then it is more likely that a caesarean section will be suggested rather than induction of labour with a preterm breech baby.
If a baby is found to be breech at 36 weeks, it is usual to refer to the hospital to discuss and plan the mode of delivery for a breech baby.
A scan is done to check the following things:
Placenta position - a low lying placenta (praevia) can lead to breech presentation, and one third of women with a praevia do not have any bleeding, which would normally alert to this problem. Often the scan at around 18 to 20 weeks may have already ruled this out.
Baby and his position - now that ultrasound is so common at 18 to 20 weeks, it is extremely unusual to discover any abnormalities in the baby at this stage. The sonographer will check the amount of water around the baby, the exact position, and whether the baby has his neck extended looking upwards (stargazing). A weight estimation is also made.