What is optimal fetal positioning?

This topic is a real passion of mine as a midwife, and all my clients get to hear about it!

Pregnant women often ask me the question “what can I do to help my labour go as smoothly as possible?  Is there really anything I can do to help myself in preparing for labour?”

Well, we know that there is an “optimal” way for baby to line itself up for the most efficient way of manoeuvring through maternal pelvis.  And that is all to do with the widest diameter of the babies head lining up with the widest diameter of the maternal pelvis.

The ideal way for the baby to enter the pelvis is when the baby is lying on maternal left side.  This position is called LOA which stands for Left Occiput Anterior. To explain the jargon, the occiput is the back part of the baby’s head.

So the baby’s back and therefore occiput is on the maternal left, as demonstrated in the photo of my model doll and pelvis. Just to add though, the baby needs to have its chin on its chest, (we call this a flexed chin) to get through the pelvis and my doll refused to flex its chin onto its chest!! Photo  does though illustrate well position of back in maternal tummy!Image

Second most common ideal line up for the baby  is ROA i.e when the baby lines up on the maternal right.

Both the above positions encourage the baby to tuck their chin onto their chest which then helps as they enter the pelvis at the end of pregnancy or “term” or pregnancy, as well as in labour itself.

The not so favourable position is when a baby lies in an OP or occiput posterior position. i.e the baby is lying with its back up against maternal back, looking to the front of maternal tummy.

ImageIn this position the baby will not be able to enter the pelvis so easily and most will eventually rotate to a more favourable position as described above.  The knock on effect of this is that “OP” labours are often more longer (as the baby has to turn or rotate into the OA position) and so can be more tiring, and often this leads to the need for more pain relief in labour.

Additionally OP babies often do not descend into the pelvis or “engage” before labour starts. This means that you are more likely to go over your due date .

I have to dash as I have a client to attend who is in labour. When I palapated her abdomen at her last appointment her baby was in the LOA position so she is hoping for a smooth labour!

Next blog post I will write about how to get your baby to line up in the good or optimal  positions we have discussed ready for labour!