We sought to examine the evolution of postpartum anxiety, obsessions and compulsions over time, and the influence of depression on their clinical course. This was a prospective cohort of obstetric patients enrolled at a tertiary care women's hospital. Women were recruited immediately postpartum and followed for 6 months. Women were screened for depression, state-trait anxiety, and obsessive-compulsive symptoms and dichotomized by the presence of depression. Four hundred sixty-one women agreed to participate in the study and completed the 2 weeks postpartum assessment; 331 (72 %) women completed the assessment at 6 months postpartum. At 2 weeks postpartum, 28 (19.9 %) women with depression had anxiety symptoms, compared to 4 (1.3 %) women who screened negative for depression (p < 0.001). Similarly, 36 (25.7 %) women with depression endorsed obsessions and compulsions compared to 19 (8.4 %) women without depression (p < 0.001). A significant interaction effect was present with anxiety over time such that by 6 months postpartum, there were no differences in symptoms in women with and without depression (p = 0.860). Conversely, the differences in obsessions and compulsions between depressed and non-depressed women persisted (p = 0.017). Women with postpartum depression are more likely to experience comorbid state-trait anxiety and obsessive-compulsive symptoms in the immediate postpartum period. While state-trait anxiety symptoms tend to resolve with time, obsessive-compulsive symptoms persist. Understanding these temporal trends is critical to tailor appropriate monitoring and treatment.