One-year trajectories of postpartum depressive symptoms and associated psychosocial factors: findings from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

Abstract

BackgroundTrajectories of postpartum depressive symptoms up to 1 year after childbirth and the related risk factors remain unclear. Accordingly, this study aimed to examine the 1-year trajectories of postpartum depressive symptoms and their associated risk factors. MethodsA total of 22,493 pregnant women were recruited between July 2013 and September 2016 in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study in Japan. Among them, 11,668 women with no missing data were included in the analyses. Depressive symptoms were assessed at 1 month and 1 year postpartum using the Edinburgh Postnatal Depression Scale. Multinominal logistic regression analysis was conducted after adjusting for covariates. ResultsThe prevalence of depression was 13.9% at 1 month and 12.9% at 1 year postpartum. We identified four depression trajectories, i.e., “persistent (depressed throughout the 1 year postpartum)” (6.0%), “recovered (depressed at 1 month postpartum and recovered within a year)” (7.9%), “late-onset (became depressed after 1 month postpartum)” (6.8%), and “resilient (not depressed throughout 1 year postpartum)” (79.2%). Psychological distress during pregnancy was significantly associated with all trajectories (persistent: odds ratio [OR]=10.24, 95% confidence interval (CI)=8.40-12.48; recovered: OR=3.78, 95%CI=3.28-4.36; and late-onset: OR=3.96, 95%CI=3.40-4.62). LimitationsPostpartum depression was evaluated only by a self-administered questionnaire and the dropout rate was not neglectable. ConclusionsThis study highlighted the high prevalence of depressive symptoms at 1 year postpartum and found that half of the depressive symptoms at 1 year were late-onset. The findings suggest the necessity of long-term follow-up (up to 1 year) for perinatal mental health.