ObjectivePregnant patients are vulnerable to both depression and sleep-disordered breathing, and both convey risks for maternal and fetal outcomes. Previous research has indicated that sleep-disordered breathing is associated with depression, but further information related to the risk of depression based on timing of onset of snoring is needed. DesignWhen presenting to clinic for their initial prenatal visit, pregnant patients completed a packet of questionnaires, which included measures related to depression (Edinburgh Postnatal Depression Scale) and snoring. Habitual snoring was defined as snoring 3 or more nights per week. ResultsIn total, 1367 women were included and 34.1% reported habitual snoring, either chronic (24.4%) or pregnancy-onset (9.8%), with increased frequency of pregnancy-onset habitual snoring in later stages of pregnancy. Unadjusted analyses suggested increased odds of depressive symptoms in chronic and pregnancy-onset habitual snoring groups relative to nonsnorers (odds ratio [OR]: 2.01, 95% confidence interval [CI]: 1.39, 2.92, P < .01; OR: 2.50, 95% CI: 1.54, 4.07, P < .01, respectively). These findings were maintained after adjusting for maternal age, marital status, gestational age, and parity (chronic habitual snoring OR: 1.69, 95% CI: 1.14, 2.53, P < .01; pregnancy-onset habitual snoring OR: 2.79, 95% CI: 1.35, 5.78, P < .01). ConclusionsMaternal snoring may be a risk factor for prenatal depressive symptoms. Pregnancy-onset habitual snoring confers additional risk for depression compared to not snoring during pregnancy.