I hadn’t heard of ‘posterior fetal presentation’ until I went for a midwife check-up at around 36 weeks pregnant with my daughter. I had noticed that my bump had been looking a little lopsided, with something hard and fidgety just above my belly button (which turned out to be her feet!) but I had previously just been happy knowing she was head down.
So, what is posterior position and what does it mean for birth?
What is posterior fetal presentation?
Occipito-posterior fetal position is where the baby is spine-to-spine with the mother, as opposed to occipito-anterior, where the baby’s back is pointing towards the mother’s belly button.
The anterior position is ideal for birth because in this position, baby will fit through the pelvis more easily as the back of the head will press more evenly on the cervix, helping it to open as labour progresses. In the posterior position, labour can be prolonged and pains can be felt more in the mother’s back.
Interestingly though, in the first stage of labour, up to one-third of babies are in the posterior position and it is something health professionals are experienced in handling on a regular basis.
What causes posterior fetal presentation?
There has been a rise in cases of posterior babies at the time of birth over the past decade. Research suggests a number of reasons for this; including the expectant mother spending a lot of time seated at a desk, in bucket seats in cars, or leaning back on the sofa, with less time spent seated in an upright position. This is because the heaviest part of baby – his back – will naturally move towards the lowest side of the mother’s abdomen, in-line with gravity. Therefore, if the mother’s pelvis is regularly lower than her knees, baby’s back would be more likely to settle against the mother’s back. Some research also suggests that a small pelvis in the mother can mean that baby has a tough time rotating once the forehead is settled into the narrow pubic bone.
What can you do to turn baby?
The good news is that most babies who are in a posterior position early on in labour will rotate during active labour or just before birth, with only around 5 in 100 remaining in the posterior position throughout labour and birth.
At my check-up appointment, the midwife explained that there were various exercises I could try to ‘spin’ baby and I went home to google as much as I could about getting my little one to turn. The most popular suggestions seemed to be to spend as much time as possible in a forward-tilted position, whether that be leaning over a birthing ball, sitting in a chair with your knees lower than your pelvis, or crawling around on all fours. I tried them all (including one method that involved an ironing board which I do not recommend!) and my daughter remained stubbornly in her spine-to-spine position until she emerged ‘sunny side up’.
What it meant for my labour
My daughter was 12 days overdue and early labour was rather prolonged, however as she was my first, I don’t have a comparison for reference. Yes, it hurt but I had expected that. The contractions were particularly strong in my back so I made the most of a rented TENS machine to fire electrical pulses through my lower back. This is said to kickstart the body’s natural painkillers and it was definitely a welcome distraction, as was gas and air. A forward-facing position in the birthing pool helped me during active labour as the water seemed to take the weight off my back, particularly as I was unable to sit comfortably on my bottom or lie backwards without feeling a lot of pressure against my spine.
Harriet was born after around six hours in active labour, with no complications. While I’d recommend trying to encourage your baby to turn if you can and if you are aware of his position before labour, I also want to reassure any anxious mothers that you can still have a straightforward birth even if baby stubbornly refuses to turn.
Jen Dowding, Baby massage and baby yoga instructor, Basking Babies Laindon & Orsett