Breech Presentation: An Overview
Breech presentation refers to a position adopted by the foetus inside the uterus. Most babies tend to lie with their head down towards the cervix. This is the normal position and most conducive to normal deliver. Some babies may lie with their foot or buttocks facing the cervix. This position is called breech. This position is of importance because a normal delivery is very difficult when the foetus is in breech position and there is a chance of high foetal and maternal deaths and disability due to this position of the foetus.
It occurs in 1-4% of deliveries worldwide and the incidence of breech presentation reduces as gestational age increases. The common causes of breech presentation include prematurity, twins, uterine malformations or fibroids, placenta previa, foetal malformations like absence of head or neck masses and excess amniotic fluid (liquor).
The commonest cause for breech presentation is prematurity. 1 in five preterm infant with a breech presentation will have some birth defect. Many babies may lie in the breech position during the early months of pregnancy, but most will adopt the normal cephalic lie by the start of 28th week.
Breech presentation is usually diagnosed in the third trimester of pregnancy. If your baby is found to have breech presentation, then you will be under observation to see if the baby corrects its position spontaneously. There are fair chances of this happening so waiting till 34-36 weeks is appropriate. In fact there are records of babies who have corrected position even after onset of labour.
If however the breech position does not correct, then delivery by a caesarean section is the safest way to deliver the baby with least harm to babies and mothers. Vaginal deliveries of breech presentation were the norm till 1959, but considering the risks of death and injuries to the foetus in a vaginal delivery, vaginal delivery has nearly been abandoned and it is now retorted to only in cases of a non cephalic second twin, foetal demise or precipitous labour (a sudden and very fast delivery).
Presently nearly 90% of all breech presentations are delivered by caesarean section. Although caesarean section has reduced the rates of birth injuries and other foetal problems, it has increased maternal morbidity due to the effect of surgery.
In the 1960’s and 70’ external cephalic version for breech presentation was quite popular, but rapidly went in to disuse following some reports of foetal death. It again reappeared towards the 90’s; it is a safe alternative to vaginal breech delivery or caesarean section. It reduces the need for caesarean section by half and all women with breech presentation are advised external cephalic version at term by the American College of Obstetricians and gynaecologist.Summary
- Breech presentation is seen in 1-4% of all deliveries.
- Commonest causes include prematurity and twins
- Increased rates of foetal birth injury and deaths
- Incidence of breech presentation decreases with gestational age
- Vaginal delivery was the norm before 1959, but now nearly 9/10 breech presentations are delivered by caesarean section
- External cephalic version is a safe and effective method for correction of breech position. It can prevent up to 50% of caesarean sections and is recommended to all women at term with breech presentation.