People often urge moms-to-be to get plenty of sleep before the baby comes. Now, researchers report that good sleep during pregnancy might also lower the risk of premature delivery, reports  UPI.

The review of published studies provides important information for pregnant women and their doctors, said lead researcher Jane Warland, an associate professor at the University of South Australia.

“Adults sleep for a third of their lives, so too an unborn baby is asleep for a third of their gestation, so it makes sense that maternal sleep could have an impact on the health of the fetus,” she said in a university news release.

“We already know that if a mother sleeps on her back, it can negatively impact the unborn baby, probably by reducing the delivery of oxygen and nutrients to the placenta,” Warland explained.