Here's Why You Really Should Sleep On Your Side When Pregnant

It's more dangerous than you think.
Sleeping on your side is linked with fetal well-being.
Sleeping on your side is linked with fetal well-being.

Like pregnant women needed another reason to keep them up at night.

Most of us already know that we should sleep on our sides in the later stages of a pregnancy, but a new study that's the first to monitor unborn babies and a mother's sleep position overnight tells us exactly how important this is.

A fetus is less active overnight when a woman sleeps on her back, which can increase the risk of stillbirth, according to research out of The University of Auckland.

These new findings come just days before Pregnancy and Infant Loss Awareness Day on Oct. 15. In Canada, about one in 125 pregnancies end in a stillbirth (the death of a fetus in the uterus after 20 weeks gestation), according to Statistics Canada.

The Auckland study, published this week in The Journal of Physiology, studied 30 pregnant women in their third trimester.

All of the women in the study were healthy, with healthy babies. Using infrared cameras to track sleep position, and electrocardiogram (ECG) devices to monitor the heart-rate of the mothers and the babies, researchers found that the fetuses were only in an active state when the mothers slept on their left or right sides.

Fetal activity is a measure of its well-being, the researchers said.

Researchers recommend lying on your side during pregnancy.
Researchers recommend lying on your side during pregnancy.

"In the situation where the baby may not be healthy, such as those with poor growth, the baby may not tolerate the effect of maternal back sleeping," Peter Stone, one of the lead investigators, said in a release.

We are suggesting that there is now sufficient evidence to recommend mothers avoid sleeping on their back in late pregnancy, not only because of the epidemiological data but also because we have shown it has a clear effect on the baby.Lead Investigator Peter Stone

The study is part of a growing body of research that links a mother's sleep position with stillbirth. Researchers in the U.K. recently found that women who slept on their back were twice as likely to suffer a stillbirth as those who slept on their left side.

But for women who find sleeping on their side unnatural or uncomfortable (what isn't uncomfortable in the third trimester, though?), this news could just add to their sleepless nights. According to the National Sleep Foundation, 78 per cent of women report disturbed sleep during pregnancy.

The good news? Body pillows can help make side-sleeping "slightly-less horrible."

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