All too often I hear of moms being told they need to have a C-section, as their baby is “too big”. Many are told in labour that the baby is stuck and that a Caesarian section is necessary. Most babies won’t grow too big for their mothers, but on occasion they can. It may be detected in the last few weeks of pregnancy as the baby never engages in the pelvis, or it may be picked up in labour.
Here are a few reasons why a “vaginal bypass” may be necessary:
1. Your baby is simply too big for your pelvis
This is medically known as cephalic pelvic disproportion. In basic terms, the head is just too big to fit the pelvis. The head is the biggest part of the baby to pass through the pelvic outlet and it is a rather snug fit. If the baby does not descend into the pelvis in the last few weeks of pregnancy you may be told that a natural delivery is unlikely.
2. The baby is in the wrong position for delivery
The best position for a vaginal birth is when the baby is head down. This is known as a cephalic or vertex presentation. This is the most common and natural position for the baby to assume for delivery. In some cases the baby assumes a different position. This may be sideways or transverse, or it can be bum first or breach. If the baby is presenting in any position other than head first, a C-section delivery is often recommended. On occasion, the baby may be in the optimal head first position but lying posterior. This means that his back is towards your back. In this case, your labour may be long and slow. The baby may not be able to be born vaginally and a C-section will be recommended.
3. You may have an irregular shaped pelvis
It may be small or it may have an unusual diameter. You may previously have sustained an injury to the pelvis, or you may have just been born that way. This can mean that while labour progresses nicely and you’re dilating well, the baby may be unable to negotiate the birth canal and, in essence, get stuck. Throughout labour, the baby’s progress down the birth canal will be closely monitored. If the baby starts showing signs of difficulty passing through this passage a C-section will be advised.
4. Shoulder girdle dystocia
This is when the head of the baby passes nicely out of the vaginal opening but the shoulders get stuck. Usually the shoulders are born one at a time as the baby eases out into the world, but it can happen that both shoulders present at the same time and so get stuck. This is an obstetric emergency and measures will need to be taken to deliver the baby quickly. This may happen in the case in the birth of a very large baby.
5. Your position in labour
The more mobile you are in labour the better your delivery will be. Getting up, walking around or swaying can help loosen up the pelvic ligaments and widen the outlet. Lying flat on your back will possibly slow down your labour, making a vaginal birth longer and perhaps more difficult.