Association between adverse perinatal events and postpartum depressive symptoms in a North American prospective preconception cohort study

Background: Identifying risk factors for postpartum depression (PPD) is critical to inform early intervention efforts. This study investigated the impact of adverse perinatal events on PPD. Methods: We analyzed data from the Pregnancy Study Online (PRESTO), a North American prospective preconception cohort study. Participants (N = 3559) aged 21-45 years completed questionnaires at preconception, during pregnancy, and postpartum. PPD was assessed at six months postpartum using the Edinburgh Postnatal Depression Scale (EPDS). We fit generalized linear models to estimate risk ratios (RRs) and 95 % confidence intervals (CIs) for the associations of adverse perinatal events (preterm birth; birth size for gestational age; infant birthweight; and NICU admission) with PPD (EPDS score >= 13), adjusting for confounders including preconception mental health. Results: A total of 9.8 % reported PPD. Preterm birth (i.e., <37 weeks gestational age; RR = 1.30; 95 % CI: 0.92, 1.82), particularly spontaneous preterm birth (RR = 1.38; 95 % CI: 0.90, 2.10), very preterm birth (<34 weeks; RR = 1.88; 95 % CI: 1.04, 3.35), very low infant birthweight (i.e., <1500 g; RR = 1.67, 95 % CI: 0.77, 3.60), and NICU admission (RR = 1.15; 95 % CI: 0.86, 1.55) were associated with increased PPD risk. Stratified analyses indicated preterm birth was more strongly associated with PPD among parous participants and participants with a history of mental health diagnoses. Conclusion: Adverse perinatal events were associated with an increased risk of PPD at 6 months postpartum. Early identification and management of depressive symptoms in those who have experienced adverse perinatal events are crucial for improving both parental and infant health outcomes.