Abstract
BACKGROUND: Prenatal maternal depression affects an estimated one in five women, with implications not only for the mother but also for the child, associating negatively with offspring mental health and cognition. This study aimed to investigate multiple outcomes within the same set of participants from multiple cohorts, explore sex-specific differences in associations, and examine of the role of timing of maternal depression. METHODS: We performed large-scale individual participant data analyses with a sample size of up to 76,514 participants to investigate prospective associations between prenatal maternal depression and eight offspring behavioural and developmental outcomes, leveraging harmonised data from seven European birth cohorts. Cohort-specific estimates were combined using random-effects meta-analysis. Potential sex differences and the role of pre-pregnancy and postnatal depression in the associations were examined. FINDINGS: Prenatal maternal depression was associated with higher internalising, externalising, attention deficit hyperactivity disorder, and autism spectrum disorder symptoms (6.61-10.90 increased percentile scores). Associations were similar between males and females, largely independent of pre-pregnancy depression, and partially mediated by postnatal maternal depression. Continuous prenatal depressive symptoms were associated with all eight offspring outcomes. INTERPRETATION: These findings emphasise the importance of prenatal maternal depression as a key developmental risk factor. Future work should consider how best to support mental health during pregnancy and children exposed to prenatal depression. Our results contribute to the growing evidence underscoring the need for early intervention and tailored support for those experiencing depression during pregnancy. FUNDING: HappyMums Project, funded by the European Union (Grant Agreement n.101057390).