Mothers-to-be who snore are more likely to give birth to smaller babies, a study has found.
Snoring during pregnancy was also linked to higher rates of Caesarean delivery. Experts said snoring may be a sign of breathing problems that could deprive an unborn baby of oxygen.
Previous research has already shown that women who start to snore during pregnancy are at risk from high blood pressure and the potentially dangerous pregnancy condition pre-eclampsia.
More than a third of the 1,673 pregnant women recruited for the new US study reported habitual snoring.
Scientists found that women who snored in their sleep three or more nights per week had a higher risk of poor delivery outcomes, including smaller babies and Caesarean births.
Chronic snorers, who snored both before and during pregnancy, were two thirds more likely to have a baby whose weight was in the bottom 10 per cent. They were also more than twice as likely to need an elective Caesarean delivery, or C-section, compared with non-snorers.
Dr Louise O’Brien, from the University of Michigan’s Sleep Disorders Centre, said: “We have a window of opportunity to screen pregnant women for breathing problems during sleep that may put them at risk of poor delivery outcomes.”