Pregnant women advised to sleep on side to help prevent stillbirth

Pregnant woman sleeping on side

New research suggests the risk of stillbirth doubles if pregnant women go to sleep on their backs in the third trimester

Finding a comfortable position to fall asleep in isn't easy during pregnancy – and doctors are now ruling out one of the options. They're advising women in their third trimester to avoid falling asleep on their backs, in light of new research which confirms that the position doubles the risk of stillbirth.

The findings, published in the British Journal of Obstetrics and Gynaecology, show that women who go to sleep in the supine position are at 2.3 times the risk of late stillbirth (after 28 weeks' gestation), compared with women who go to sleep on their side.

Why should you go to sleep on your side during pregnancy?

The Midlands and North of England Stillbirth Study (MiNESS) of more than 1,000 women, confirms findings from earlier studies in New Zealand and Australia. Although researchers cannot say for certain why the risk is increased, there are several theories.

In the third trimester, when a woman is lying on her back, the combined weight of the baby and uterus puts pressure on the main blood vessels that supply the womb – this can restrict blood flow and oxygen to the baby. Another possible explanation is disturbed breathing during sleep, which is worse when a woman is on her back.

Whether they're going to bed for the night or hoping for a daytime nap, women in the third trimester are being advised to go to sleep on their sides as a result of the findings. But researchers are also stressing that women should not be too concerned if they wake up on their backs – the going-to-sleep position is the one held longest during the night, so women should roll on to their side if they wake up this way.

The study was led by Professor Alexander Heazell, the clinical director at the Tommy's Stillbirth Research Centre at St Mary's Hospital, Manchester. She reported that around 11 babies are stillborn every day in the UK, and advised women about what they could do to help prevent that from happening.

“Stillbirth is devastating, with long-lasting effects on bereaved parents. Parents want to know why their baby has died, whether it might happen again if they try for another baby and what they can do to avoid further stillbirth.

“The MiNESS results indicate that if women go to sleep on their side while pregnant, rather than on their back, there could be 3.7 per cent reduction in stillbirth.”

The study suggests that in the UK alone, around 130 babies could be saved each year if women went to sleep on their side during the third trimester. Globall researchers estimate that falling asleep in this way could save up to 100,000 babies annually.

Tips for going to sleep on your side in the last three months of pregnancy

  • Put a pillow or pillows behind your back to encourage side-sleeping
  • If you wake during the night, check your position and go back to sleep on your side
  • Pay the same attention to sleep position during the day as you would during the night
  • If you wake on your back during the night, don't worry, just roll on to your side