Gestational hemodilution as a putative risk factor for postpartum depression: A large-scale nationwide longitudinal cohort study.

Background: While anemia during pregnancy has been linked to increased postpartum depression (PPD) risk, longitudinal studies on the association between gestational hemodilution, represented by decreased hematocrit (Hct) during the transition from the 1st to 2nd trimester, and PPD risk, are scarce. The current study aimed to investigate this association in a nationwide cohort over the perinatal period.

Methods: This retrospective cohort study included 104,715 women who gave birth between January 2008 and December 2015.