Mothers-to-be who sleep on right side 'risk stillbirth'

Published on Tuesday 14 June 2011 16:25

Women who sleep on their right side or back during late pregnancy could be at increased risk of stillbirth, research suggests.

Experts found a link between sleeping position and the chance of late stillbirth (28 weeks or over) in a study of more than 450 women.

The overall risk of late stillbirth was small - just three per 1,000 births - but researchers said the findings needed "urgent confirmation" in other studies.

Some 155 women who had a late stillbirth were questioned about their lifestyles, and compared with 310 women who went on to have healthy pregnancies.

The research found that women who slept on their back or on their right side were twice as likely to experience stillbirth compared with women who slept on their left side.

The absolute risk of late stillbirth for women who went to sleep on their left was 1.96 per 1,000 births but rose to 3.93 per 1,000 for women who slept in any other position.

The risk seemed to be slightly higher for women who went to sleep on their back.

The findings held true even when factors such as age, smoking status, body mass index and social deprivation were taken into account.

Previous studies have found that a woman's position in late pregnancy, either when resting or giving birth, can have an impact on cardiac output and the delivery of oxygen to the foetus.

The womb seems to exert greater pressure on blood vessels when the mother lies on her back or her right compared with on her left, thereby decreasing blood flow.

Writing online in the British Medical Journal, the experts, who included professors, researchers and lecturers from the University of Auckland, called for further studies to test the findings.

They said: "If our findings are confirmed, promoting optimal sleep position in late pregnancy may have the potential to reduce the incidence of late stillbirth."

But in an accompanying editorial, Dr Lucy Chappell, from King's College London, said there may be several reasons for the findings and "a forceful campaign urging pregnant women to sleep on their left side is not yet warranted".

She added that more research was needed.

Janet Scott, research manager at the charity Sands, said: "More than 1,200 babies a year are stillborn in the final weeks of pregnancy, and a third of stillbirths have no clear cause at all.

"Mums want to know what they can do to reduce the chance of this happening to their baby.

"A simple message which mums could follow, which would reduce their risk of stillbirth, would be very welcome."

Daghni Rajasingham, spokeswoman for the Royal College of Obstetricians and Gynaecologists, said: "More research is needed into sleep patterns before any firm conclusions over sleeping positions can be made.

"In the meantime, women should speak to their midwives if they are concerned."