In 2009, researchers presented a preliminary study at the Associated Professional Sleep Societies meeting in Seattle, Washington regarding a possible connection between pregnancy-onset snoring and preeclampsia and gestational hypertension. Both conditions can be a health risk to the fetus and pregnant woman. In September 2012, the final version of the study was published in the American Journal of Obstetrics and Gynecology.

Data for the study was collected from 1,719 women receiving prenatal care from clinics at the University of Michigan. All women were 18 years or older and at least 27 weeks pregnant at the time. The control group consisted of women between 18 and 45 receiving general gynecological care from the same clinics. All data was collected between Mar. 2007 and Dec. 2010.

Pregnant and non-pregnant women in the study were screened for snoring habits. About 34% of the pregnant women claimed they snored, but only 15% of the controls made the same claim. One-quarter of the pregnant women claimed the snoring did not start until they became pregnant. All groups were then screened for hypertension (chronic and gestational) and symptoms of preeclampsia. Pregnant women who reported snoring were more likely to suffer from hypertension, of both kinds, and preeclampsia. The rate of hypertension and preeclampsia was even greater in the study population who reported pregnancy-onset snoring.

Conclusion: Researchers claim this study is the largest of its kind to correlate snoring during pregnancy and pregnancy complications, particularly hypertension and preeclampsia. They also noted that gestational diabetes rates did not increase in the snoring group. Authors claim up to 19% of pregnancy disorders associated with hypertension may be avoided with snoring treatment.

Source: O'Brien LM, Bullough AS, Owusu JT, et al. Pregnancy-onset habitual snoring, gestational hypertension, and preeclampsia: prospective cohort study. Am J Obstet Gynecol 2012;207:x.ex-x.ex.