Prenatal antidepressant use and longitudinal differences in BMI up to 8 years of age in the offspring born to mothers with depression/anxiety in the Norwegian Mother, Father and Child Cohort Study

No study has explored how prenatal antidepressant exposure affects offspring body mass index (BMI) throughout childhood. We used data from the Norwegian Mother, Father, and Child Cohort Study (MoBa) linked to the Medical Birth Registry of Norway and the MoBa Genetics. We included 6084 pregnancy-child dyads (singleton, liveborn) with child BMI data up to 8 years, born to women with pre-pregnancy depression/anxiety. Prenatal antidepressant exposure groups include continued antidepressants in pregnancy ( n = 626), discontinued antidepressants proximal to pregnancy ( n = 412), or unexposed to antidepressants ( n = 5046). Mean BMI differences over time between groups were calculated using multilevel mixed-effect linear models. Children born to continuers had comparable childhood BMIs with those born to unexposed mothers or mothers who discontinued antidepressant, in overall and in both sexes. However, higher BMI was observed up to 3 years among male offspring of continued mothers compared to discontinuers in those exposed to selective-serotonin-reuptake-inhibitor before pregnancy (β = 0.334; 95% CI: 0.081 to 0.588 at baseline). Lower BMI was seen among female offspring born to continued vs. discontinued mothers with larger gap over time, especially between low-moderate use of antidepressant vs. discontinuation during pregnancy. Analyses integrating parental genetic liability for depression, BMI, and antidepressant response using polygenic risk scores in ( n = 1913) suggests potential influence of the genetic component on the longitudinal differences in BMI in some strata. The childhood BMI of children born to mothers with pre-pregnancy depression/anxiety did not differ across prenatal antidepressant trajectories. Exploratory analyses revealed differences at specific timeframes which are sex-specific and potentially influenced by genetic liability profiles. • Longitudinal BMI throughout childhood of children born to mothers with pre-pregnancy depression/anxiety does not differ across prenatal antidepressant exposure trajectories. • Exploratory analyses revealed differences at specific times of growth which might be sex-specific and potentially influenced by parental genetic liability profiles.