The purpose of this study is to prospectively examine peripartum changes in partnership characteristics among women with and without anxiety and depressive disorders prior to pregnancy. In the prospective-longitudinal Maternal Anxiety in Relation to Infant Development (MARI) study, n = 306 expectant mothers completed up to seven waves of assessment from early pregnancy until 16 months postpartum. Lifetime anxiety and depressive disorders according to the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) were evaluated at baseline using the Composite International Diagnostic Interview for Women (CIDI-V, Martini et al. 2009). Partnership characteristics were assessed during pregnancy as well as 4 and 16 months postpartum using the Partnership Questionnaire (Hahlweg 1996). Linear regressions were applied to test associations between diagnostic status prior to pregnancy and peripartum partnership characteristics. Compared to women without anxiety and depressive disorders prior to pregnancy, women with comorbid anxiety and depressive disorders reported less tenderness during pregnancy, less postpartum tenderness, satisfaction, and overall partnership quality as well as a lower decrease in communication from pre- to postpartum. Women with pure depressive disorders and comorbid anxiety and depressive disorders prior to pregnancy indicated a higher increase in quarreling from pre- to postpartum. Findings suggest that women with depressive (and comorbid anxiety) disorders prior to pregnancy are at elevated risk for an unfavorable peripartum partnership development and might thus profit from targeted family interventions during this period.