Bais B, et al. - This study evaluated seasonal influences on antepartum depressive symptoms. In this study, 13.2% of pregnant women displayed an Edinburgh Postnatal Depression Scale (EPDS) ≥ 9. Seasonal fluctuations of symptoms were observed in healthy women with a peak in winter. An inverse pattern of seasonality was observed among women treated for psychiatric symptoms. The full heterogeneous study sample displayed no seasonal differences. Subgroups of women differed regarding seasonal influences on antepartum depressive symptoms.