AbstractHypertensive disorders of pregnancy (HDP) may increase the risk of offspring depression in childhood. Low birth weight is also associated with increased risk of mental health problems, including depression. This study sought to investigate (a) whether there is an association between HDP and the risk of depression in childhood and (b) whether low birth weight mediates this association. The current study is based on the Avon Longitudinal Study of Parents and Children (ALSPAC), a prospective, population-based study that has followed a cohort of offspring since their mothers were pregnant (n = 6,739). Depression at the age of 7 years was diagnosed using parent reports via the Development and Well-Being Assessment (DAWBA). Log-binomial regression and mediation analyses were used. Children exposed to HDP were 2.3 times more likely to have a depression diagnosis compared with nonexposed children, adjusted Risk Ratio [RR], 2.31; 95% CI, [1.20, 4.47]. Low birth weight was a weak mediator of this association. Results were adjusted for confounding variables including antenatal depression and anxiety during pregnancy.This study suggests that fetal exposure to maternal hypertensive disorders of pregnancy increased the risk of childhood depression. The study adds to the evidence suggesting that the uterine environment is a critical determinant of neurodevelopmental and psychiatric outcomes.