Sleeping on your back during the third trimester of pregnancy could double your risk of stillbirth, according to a new study conducted by Tommy’s Stillbirth Research Center in Manchester and published in the International Journal of Obstetrics and Gynecology. While the information confirms what several prior studies have suggested, experts are cautioning women to take the findings with a grain of salt.
“What I don’t want is for women to wake up flat on their back and think ‘oh my goodness I’ve done something awful to my baby,” Alexander Heazell of the Stillbirth Research Center told the BBC.
Stillbirths are more common than one would think (or hope). In the United States alone, 24,000 babies are stillborn each year. Actionable advice could help women decrease the rates of stillbirth, and the potential link between sleeping position and still birth has been examined extensively. A previous study conducted in Australia and New Zealand found a correlation between the supine sleeping position and late-term stillbirth and other studies have found similar correlations. But until now, these findings were all based on small sample sizes. This new study by Heazell and colleagues is the first of its size to find a relationship between sleeping position and pregnancy risks in the third trimester.
The study followed about 1,000 women in the UK who were experiencing their first pregnancies. Roughly 300 had stillbirths and 700 had normal births. Twenty-five days after birth, the researchers interviewed each woman to ask about her sleeping position in the final trimester. They found that those who reported going to sleep on their backs were about twice as likely as those who slept on their sides to have stillbirth.
While the study is the largest so far, it does have its limitations. Because the interviews happened 25 days after the birth, some memory recall could be clouded or biased. It’s also possible that some of the women who had stillbirths had an unknown health factor that wasn’t discovered during the questionnaire. There’s also no clear reason why sleeping on your back during the final trimester would be dangerous.
As a result of the study, Heazell and colleagues suggest pregnant women make every effort to sleep on their sides, and to place pillows behind their backs to help them fall asleep on their sides. The researchers say that this change could decrease stillbirth rates in the UK by 3.7 percent. And that’s no small relief for women worried about stillbirth. One woman who had a stillbirth and then had a subsequently successful pregnancy and birth told The BBC that was relieved to have access to the new information in this study.
“I really think it helps to empower people, as it feels like something you can go away and do with the hope of having a more healthy pregnancy and a better outcome than sadly lots of people have… I think having clear things that can help you feel a bit more in control is really important for women.”