Pregnant women who sleep on their backs double the risk of having a stillbirth, a new study suggests.
The research, which was recently published in the British Journal of Obstetrics and Gynaecology, found women in the U.K. had a 2.3 times more likely chance to suffer a stillbirth if they slept on their backs during the third trimester.
Study authors also estimated there would be a 3.7 per cent decrease of stillbirths in general if pregnant women slept on their sides.
Lead researcher Dr. Alexander Heazell of the University of Manchester says this study confirms earlier studies that found a link between mothers sleeping on their back and stillbirths after 28 weeks of pregnancy.
“This study also investigated whether other factors such as the stage of pregnancy, mother’s size and baby’s growth were important. None of these factors could account for the association. Therefore, the investigators think that going to sleep laid flat is a risk-factor for late stillbirth,” he tells Global News.
Researchers looked at the data from 291 women who had a stillbirth and 733 who had a live-born baby from 41 maternity units in the U.K. Data was collected using an interviewer-administered questionnaire, and women were asked about their sleeping habits before pregnancy and on the night before the interview/stillbirth.
“This study confirms that supine going-to-sleep position is associated with late stillbirth. Further work is required to determine whether intervention(s) can decrease the frequency of supine going-to-sleep position and the incidence of late stillbirth,” authors noted.
Heazell says he wasn’t completely surprised by the results because previous studies have found similar conclusions.
“What was the most interesting was the effect size,” he adds. “ was very similar in all studies, this suggests that the association we have seen is real.”
In Canada, there was a total of 2,774 stillbirths in 2012. According to the University of Ottawa, these births are more common in multiple births (the U.K. study, however, did not interview women who had multiple births).
Other studies have also found similar results. One report published in The Physiological Society from earlier this month found that fetuses were less active when women slept on their back — which can increase the risk of stillbirths.
Sleeping on your back
And if you have been sleeping on your back, Heazell says there is no need to alert your doctor right away.
“Our studies found that women who had slept on their backs in the preceding four weeks had no increased risk of late stillbirth. It seems to be related to the night before their baby died,” he says.
He adds the study specifically looked at going-to-sleep positions versus the position the mother woke up in.
“This is because people can reliably report the position that they go to sleep in, but cannot really do anything about the position in which we wake up. This makes a degree of sense in that the position we go to sleep in is the one that is held for the longest period of time.”
Dr. Noor Ladhani, an assistant professor in maternal fetal medicine at the University of Toronto, says that in general, women should try sleeping on their sides.
“We know that when women sleep on their backs, venous return is compromised, which will also make the woman feel unwell, and so we always encourage women to at least try to sleep on their sides,” she tells Global News.
“Stillbirth is so hard because many times we don’t know why it happened, so even though there are limitations in this study, it is welcome news that the risk can be reduced by this simple intervention.”
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