Supine sleep position during pregnancy associated with late stillbirth

A study, published in the British Journal of Obstetrics and Gynaecology (BJOG), found that women who sleep on their backs had at least twice the risk of a stillbirth after the 28th week of pregnancy than those who sleep on their left side.The researchers estimate that if no pregnant women slept on her back, late-stage stillbirths could fall by 3.7 percent in England.

Stillbirth, the death of a baby before birth, is a tragedy for mothers and families. One approach to reduce stillbirths is to identify factors that are associated with stillbirth. There are few risk factors for stillbirth that can be easily changed, but this study is looking at identifying how mothers may be able to reduce their risk.

Experts say pregnant women may find themselves sleeping in a variety of positions during a single night but should try to start on their side.This is because research has shown that the position we go to sleep in is the one that we spend the most time in while asleep.They say women who wake up on their backs shouldn't worry but should roll back on to their side.

In a Prospective case-control study, the researchers interviewed 291 women who had a stillbirth and 733 women who later had a live born baby in 41 UK maternity units.The mothers who had a stillbirth were interviewed as soon as practicable after their baby died. Mothers who had a live birth were interviewed during their pregnancies at the same times in pregnancy as when the stillbirths occurred.Mothers of twins or those who gave birth to a baby with major abnormalities were not included in the study.

It was found that women who had a late stillbirth were 2.3 times more likely to report going to sleep on their back on the night before the baby died compared to pregnant women who went to sleep on their left-hand side.The researchers also found that the link between going-to-sleep position and late stillbirth was not affected by the duration of pregnancy after 28 weeks, the size of the baby, or the mother's weight.An interesting finding was that women who got up to go to the toilet once or more each night had a reduced risk of stillbirth.

The researchers say could not conclude why sleep position is important for stillbirth risk. One plausible explanation is that in late pregnancy, the combined weight of the baby and the womb may compress blood vessels and restrict blood flow and oxygen to the baby.

Similar results have been found in previous studies in Australia and New Zealand.

This simple but important message should be communicated effectively to all would be mothers that it is a simple change that can make a difference for a safer pregnancy. The experts feel that the research findings are a great example of how through making small changes we can begin to bring down stillbirth rates.