Ask an expert: Is sleeping position in pregnancy really that important?

22nd Dec 17 | Parenting

A foetal medicine professor explains why advice around sleeping on your side during late pregnancy is important.

Pregnant woman is having a nap

I’m pregnant – does the position I sleep in matter?

Peter Stone, a professor of maternal foetal medicine at the University of Auckland in New Zealand, led a recent study investigating pregnancy and sleep position, which involved filming them as they slept and monitoring the heart rate of the mother and their unborn child through the night.

He says: “A definite yes, the position you sleep in does matter – certainly in late pregnancy, after 28 weeks, or seven months.

Pregnant woman sleeping on her side in bed (Thinkstock/PA)(Thinkstock/PA)

“A number of large case control studies from all over the world, and now one from the UK, all show that maternal sleep position is an independent risk factor for stillbirth.

“That means regardless of, or in addition to, other risks such as smoking, a poorly growing baby, maternal age and so on, sleep position has its own effect. The population attributable risk – that is the effect that sleep position has on the numbers of stillbirths – is over 9%, which will equate to probably more than 2,000 babies per year in the UK.

“My research has attempted to look at plausible mechanisms and we are researching the foetal activity states which are clearly affected by maternal position, and that’s what we published.

“We have also recently shown that maternal supine position – lying on the back – reduces the mother’s cardiac output and lowers aortic blood flow and is likely, therefore, to reduce blood flow to the placenta.

“So we believe now there’s enough data to give a clear public health message that in late pregnancy, maternal back sleeping is disadvantageous to the developing baby- thus sleep side not back!”

© Press Association 2017