Pregnant women who sleep on their backs are at greater risk of having a stillbirth, a new study suggests. Mothers-to-be in Ghana who slept in this position were found to be five times more likely to have a baby with a low birth weight, and for some women this resulted in a stillbirth, the researchers said. The researchers also claimed that more than a quarter of cases of stillbirth might be avoided simply by ensuring that women change their sleeping position. The study was conducted in Ghana where between 20 and 50 of every 1,000 babies are stillborn, compared with just 3.5 per 1,000 in the UK. But a recent study in New Zealand suggests that supine sleep - the technical term for sleeping on your back - is linked to higher stillbirth rates in high income countries, too. The study's senior author, Louise O'Brien, from the University of Michigan, said: “If maternal sleep position does play a role in stillbirth, encouraging pregnant women everywhere not to sleep on their back is a simple approach that may improve pregnancy outcomes.” “In Ghana, inexpensive interventions are urgently needed to improve pregnancy outcomes.” “This is a behaviour that can be modified - encouraging women to avoid sleeping on their back would be a low-cost method to reduce stillbirths in Ghana and other low-income countries.” “The data in this study suggests that more than one-quarter of stillbirths might be avoided by altering maternal sleep position.” Experts suggest that pregnant women try to sleep on their side, ideally on their left side because this can improve the blood flow to the placenta. In the new study the researchers interviewed women shortly after they had given birth at the Korle Bu Teaching Hospital in Accra, Ghana. Scientists found that those who had slept on their backs during pregnancy risked compression on the vein that carries deoxygenated blood from the lower part of the body to the heart. This means the heart is not pumping as blood as effectively as it should, which may lead to stillbirth. Researchers said the study shows that giving pregnant women simple advice on how to sleep could radically reduce the number of stillbirths. This research supports a recent Australian study which suggested that pregnant women who sleep on their backs are six times more likely to have a stillborn baby. The study, known as the Sydney Stillbirth Study, looked at the pregnancies of 295 women from eight hospitals around Australia. The five-year study found that women who sleep on their backs are six times more likely to have a stillborn baby. Lead researcher Dr Adrienne Gordon, from Sydney's Royal Prince Alfred Hospital, said previous research had suggested prolonged periods in this position restricted blood flow to the baby. The researchers added it was important that women who are currently pregnant “don’t become alarmed if they sometimes sleep on their back.”