It is generally agreed that pregnant women snore more than those who are not pregnant. Snoring in pregnancy has been associated with hypertension and is a risk factor for both preeclampsia and intrauterine growth restriction. Obstructive sleep apnea (OSA) may also be a cause of fetal compromise, since other disorders associated with maternal hypoxia can lead to adverse fetal outcomes. In this prospective observational study, both polysomnography (PSG) and the nonstress test (NST) were performed in pregnant women whose questionnaire responses suggested symptoms of OSA. Participating in the study were 35 women in whom the Berlin Scale questionnaire demonstrated symptoms of OSA. OSA was diagnosed by PSG in 4 of these women (11.4%). Two women had mild and 2 had moderate OSA. The women with OSA were older than the others and had higher body mass indices and larger neck circumferences. Two of the 4 women with OSA had gestational diabetes and one had cardiovascular disease. Three of the 31 women who did not have OSA had chronic hypertension, and 2 each had gestational diabetes, cardiovascular disease, and pregnancy-induced hypertension (preeclampsia). In 3 of the 4 cases of OSA, fetal heart decelerations accompanied maternal blood desaturation. The newborn infants had lower Apgar scores and birth weights than infants whose mothers did not have OSA. Three of the 4 infants whose mothers had OSA were admitted to a newborn healthcare unit. The investigators believe that, because early diagnosis and treatment of OSA may lessen adverse outcomes, all pregnant women should be checked for symptoms of OSA and those who are suspected should be offered PSG.