BACKGROUND: Depression and other psychiatric disorders during pregnancy and postpartum is an important health problem, especially if the symptoms are recurrent or sustained. METHODS: All Swedish speaking women attending their first antenatal care visit during three predestined weeks were invited to participate. Depressive symptoms were evaluated using the Edinburgh Postnatal Depression Scale (EPDS) in early pregnancy, two months and one year postpartum. RESULTS: In all, 2430 women completed three questionnaires. A dose-effect relation was found between the numbers of stressful life events experienced in the year prior to pregnancy and mean EPDS score in pregnancy. The prevalence of recurrent or sustained depressive symptoms (EPDS> or =12 on all three evaluations) was 3% (79/2430). Three factors were associated with depressive symptoms, two or more stressful life events in the year prior to pregnancy, native language other than Swedish and unemployment. CONCLUSIONS: Apart from questions about psychiatric history, a psychosocial history in early pregnancy including stressful life events, native language and employment status could help the health professionals to identify women at risk for recurrent or sustained depression during pregnancy and the year after giving birth.