Pregnant Women Sleeping On Their Backs May Suffer Stillbirth, Study Warns

Pregnant women should not sleep on their backs. That’s a clear warning from a new study that found lying on such position could increase the risk of stillbirth. 

The National Health Service in the United Kingdom has already considered the study for its guidance designed to reduce the number of babies who are stillborn across the country. The findings come from a large-scale international project that analyzed data from New Zealand, the U.K., Australia and the U.S.

The study, published in the journal of EClinicalMedicine, involved 851 bereaved mothers and 2,257 women with ongoing pregnancy. It shows that lying on the back from 28 weeks of pregnancy could increase the risk of stillbirth by nearly three times. 

Due to implications of the findings, the NHS has incorporated them in its Saving Babies' Lives care bundle, which provides advice to help people prevent stillbirths in the U.K.

"In later pregnancy (after 28 weeks), it is safer to go to sleep on your side than on your back," the care bundle reads. “A woman who wakes up on her back shouldn't worry, but should settle to sleep again her side."

NHS also calls on medical practitioners to encourage women to prefer sleeping on their sides even on a daytime nap.

Tomasina Stacey, lead researcher from University of Huddersfield, first reported how sleeping positions affect pregnancy in a study that focused on the relatively high rates of stillbirth in New Zealand. She initially suggested women sleeping on their backs could increase the risk of stillbirth as the weight of the uterus lowers blood flow to the baby.

"We decided to look at a range of modifiable risk factors and this was one of them," Stacey said. "The next phase is to ensure that there is consistent advice from healthcare professionals and we will be looking to see if there are ways of helping to support women to sleep in the side position.”

Stacey’s study was the first to report maternal sleep-related practices as risk factors for stillbirth, which encouraged a large-scale international project that gathered data from New Zealand, the U.K., Australia and the U.S.