The association between antidepressant continuation during pregnancy and postpartum mental health in women with obsessive-compulsive disorder (OCD) is uncertain. We identified 1317 women with live-birth singleton pregnancies and having outpatient/inpatient visits for OCD in the 4 years pre-pregnancy from the Danish registries. We defined three groups based on antidepressant prescriptions filled in the 2 years before pregnancy to delivery: (i) unexposed (n= 449); (ii) discontinuers (n= 346), i.e., with pre-pregnancy antidepressant fills only; (iii) continuers (n= 522), i.e., with antidepressant fills before and during pregnancy. We estimated crude and propensity score weighted hazard ratio (HRs) of postpartum visit for OCD and mood/anxiety disorders using Cox proportional hazard models. In weighted analyses, we found no difference in the probability of a postpartum visit for OCD or MADs with antidepressant continuation compared to unexposed and discontinuers. The likelihood of a postpartum OCD visit was higher in pregnancies having only one prescription fill during pregnancy compared to unexposed (HR = 3.44, 95% CI: 1.24, 9.54) or discontinuers (HR = 2.49, 95% CI: 0.91, 6.83). Continuers in pregnancy without antidepressant fill in the first three months postpartum had higher probability for postpartum visit for mood/anxiety disorders compared to discontinuers (HR = 3.84, 95% CI: 1.49, 9.92). Among pregnant women with pre-existing OCD, we found similar probabilities of a postpartum visit for OCD or mood/anxiety disorders in antidepressant continuers compared to unexposed and discontinuers. Continuers with a single prescription fill during pregnancy or no fill postpartum may have higher risks for these outcomes. Our findings highlight the importance of continuity of treatment throughout the perinatal period.