Timing and Cumulative Exposure of Perinatal Depressive Symptoms in Relation to Infant Rapid Weight Gain: A Prospective Longitudinal Study

Background Infant rapid weight gain (RWG) is an important predictor of later obesity. Although perinatal depressive symptoms have been linked to adverse offspring growth and development outcomes, evidence regarding their association with infant RWG remains limited, and existing studies have relied on single-time-point assessments. Objectives To examine associations of timing and cumulative exposure to perinatal depressive symptoms with infant RWG. Methods This prospective longitudinal study included 576 mother–infant dyads. Stage-specific perinatal depressive symptoms and cumulative depressive symptom burden were assessed using the Edinburgh Postnatal Depression Scale (EPDS) across seven waves. RWG was defined as an increase in weight-for-age Z-score (WAZ) > 0.67 from birth to 1, 3, or 6 months. Logistic regression and restricted cubic spline analyses were used to examine associations. Results Postnatal depressive symptoms were associated with increased odds of RWG during 0–1 month [Adjusted Odds Ratio (aOR) = 2.10, 95% confidence interval (CI): 1.05–4.17, p = 0.035], whereas no significant associations were observed for prenatal or persistent depressive symptoms. Regarding cumulative burden, each 1-point increase in cumulative average EPDS score was associated with a 10% increase in odds at 0–3 months (aOR = 1.10, 95% CI: 1.03–1.17, p = 0.005) and a 7% increase at 0–6 months (aOR = 1.07, 95% CI: 1.00–1.14, p = 0.036). Restricted cubic spline analyses suggested an approximately linear association for both periods. Conclusions Cumulative depressive symptom burden is associated with an increased risk of RWG during the first 3 and 6 months of life in a potential linear dose-response manner. The postnatal period appeared to be a critical window during which maternal depressive symptoms were associated with increased RWG risk. These findings highlight the importance of maternal mental health for early growth patterns and obesity prevention.