Does Sleeping on Your Back Increase Stillbirth Risk?
Dr. Jones: Finding a comfortable position in bed when you’re pregnant can be hard. There’s just so much of you. But can some sleeping positions be harmful to you and your baby?
A recent British study suggested that women who sleep on their backs in their third trimester of pregnancy are at increased risk of stillbirth. This shouldn’t be complicated, but it is.
Here in the studio to help us understand the strengths and weaknesses of this study are three specialists in high-risk pregnancy from the University of Utah, Dr. Martha Monson, Dr. Lauren Theilen, and Dr. Karen Gibbins. Thanks for coming, all three of you. Does that mean you disagree?
Dr. Monson: No, actually.
Dr. Theilen: No. Absolutely not.
Dr. Gibbins: This is a rare circumstance.
Stillbirth Causes and Frequency
Dr. Jones: Well, this is good news. So you all agree that there are some problems here about either sleeping on your back or this study. Let’s talk a little bit about that. I actually understand that the entire division, some 15 specialists in high-risk obstetrics, have said, ‘Wait a minute, there’s a problem with this study.’ What is stillbirth?
Dr. Theilen: This is Lauren Theilen, and we define stillbirth as the death of a fetus within the womb that happens at or after 20 weeks of pregnancy.
Dr. Jones: Okay. And how often does it happen?
Dr. Gibbins: In the United States, we currently estimate that stillbirth happens in about 1 of every 160 pregnancies. So that comes out to about 26,000 stillbirths in a year.
Dr. Jones: Well, then, what are the causes? I mean, are they all the same cause, or what’s going on here?
Dr. Monson: This is Martha Monson here, and there are multiple causes. We can go over that. Problems such as preterm labor and multiple gestations, including twins or triplets, and placental abruption, are thought to cause about one in three stillbirths, especially those that occur before 24 weeks.
Other causes, such as placental insufficiency, which leads to poor baby growth, account for about one in four stillbirths, especially after 24 weeks. Birth defects or genetic syndromes are thought to cause about 1 in 10 stillbirths, alongside infections of the baby, placenta, or mother.
Dr. Jones: So that means for the unexplained, which might include the position you’re in, that’s maybe one in four, about a quarter?
Dr. Monson: Yes, about that, a quarter of stillbirths.
Dr. Gibbins: One in four or fewer.
Examining the Study’s Methodology and Limitations
Dr. Jones: What’s the problem, if any, if pregnant women are sleeping on their backs? How many people are we talking about who are sleeping on their backs, and how did they get this number?
Dr. Gibbins: So, that’s one of the problems with the way the study was conducted. They asked women to recall how they were sleeping during their pregnancies, sometimes weeks after the stillbirth. This is like asking, ‘How did you go to bed that night?’ After such a traumatic experience, women may misremember their sleeping positions due to the stress and guilt of loss.
How Many Pregnancies Are Affected?
Dr. Jones: So it’s the way the study is conducted, and how questions are answered, that might affect this statistic. Even if the chance is 1 in 1000 of people who might have been on their back, it’s still a tiny number.
Dr. Gibbins: Correct, and when we are recommending for all pregnant women, more than 4 million women a year in this country, a small percentage of the 26,000 stillbirths, gets down to a few thousand that might be affected by this.
Dr. Jones: In any given night, a pregnant woman might be all over the bed as best she can manage.
Dr. Gibbins: Correct.
The Influence of the ‘Back to Sleep’ Campaign on Pregnant Women
Dr. Monson: The Back to Sleep campaign promotes placing newborns on their backs to prevent SIDS; it has been successful. This concept is appealing because simple behavioral changes may prevent stillbirth, but it’s a reach in this situation.
The Future of Sleep and Pregnancy Research
Dr. Jones: Regarding the biological plausibility, there may be concerns linked to obstructive sleep apnea due to snoring or sleeping on vital blood supply. A large multicenter trial is in progress that looks at about 10,000 women and retains potential findings for future research.
The Key Takeaway for Expecting Mothers and Their Partners
Dr. Gibbins: My biggest takeaway is that I want women to not feel guilty. We don’t have enough data to definitively say that sleeping on your back leads to stillbirth. The stress of trying to sleep in an unnatural position may be more detrimental. So get a good night’s sleep and grow your baby as best you can. Good luck. Thank you for joining us on The Scope.
updated: March 14, 2025
originally published: March 8, 2018
Comments are closed