Methyldopa and the risk of peripartum depression-A nationwide registry-based study

The aim of this study was to investigate the risk of maternal peripartum depression following treatment with methyldopa.

A nationwide cohort of pregnant women covering births from 1996 to 2009 was generated from nationwide registries through linkage by national person-specific health security numbers. The exposure of interest was filled prescriptions for methyldopa during pregnancy and puerperium, while filled prescriptions for labetalol or nifedipine, and no exposure were comparators. Outcomes were filled prescriptions for antidepressants or antipsychotics or admission to a psychiatric ward due to depression or psychosis. Follow-up was from conception to 6 months after delivery to assess the effect of exposure in both pregnancy and puerperium combined and from delivery to 6 months after delivery to assess the effect of exposure in the puerperium only. Risk of depression was assessed with Cox proportional hazards regression models, adjusted for propensity scores.

A total of 745 661 pregnant women were included in the study cohort covering 3620 pregnant women with exposure to methyldopa. Peripartum depression occurred in 46 cases (1.3%) after exposure to methyldopa in pregnancy and puerperium and in 53 cases (1.3%) after exposure to labetalol/nifedipine (HR = 1.12 [95% CI 0.75-1.66]). With exposure restricted to the puerperium, women developed depression in 10 cases (0.7%) after methyldopa and in 20 cases (1.0%) after labetalol/nifedipine (HR = 0.69 [95% CI 0.32-1.48]).

Maternal use of methyldopa during pregnancy and puerperium was not associated with an increased risk of peripartum depression.