Association of Prenatal Antidepressant Exposure with Trajectories and Acceleration of Body Mass Index in Children from 6 Week to 8 Years of Age

Background: Whether antidepressant exposure during pregnancy negatively affects offspring body mass index (BMI) trajectories and increments over time in childhood, is unknown.

Objectives: To determine sex-specific associations between prenatal antidepressant exposure and offspring BMI trajectories and acceleration of BMI from age 6 weeks to 8 years, accounting for confounding by genetic.

Methods:

Design: The prospective, nationwide Norwegian Mother, Father and Child Cohort Study, linked to MoBagenetics and the Norwegian Medical Birth Registry.
Setting: Nationwide in Norway. The study included 6,253 pregnancies with available data on child BMI from 6 weeks up to 8 years of age born to women with depression/anxiety prior to pregnancy.
Exposure: Maternal report on antidepressant use in pregnancy, defined as i) continued antidepressants into pregnancy (n=621); ii) initiated antidepressants in pregnancy (n=187); iii) discontinued treatment before pregnancy (n=411); or iv) unexposure to antidepressant both before and during pregnancy (n=5034).
Main outcome: Repeated measures of child BMI from 6 weeks up to 8 years of age (11 time points in total) and BMI increments per measurement.
Statistical analysis: We adjusted for confounding, including parental polygenic risk score for BMI and depression, via inverse probability of treatment weights methods. We fit growth curve models using full information maximum likelihood and an unstructured covariance. Time (i.e., child's age in years) was scaled for gestational age and postnatal questionnaire completion date. The weighted models included an interaction term between time and antidepressant exposure, child's age at baseline.

Results: Children born to women who continued antidepressant into pregnancy had a greater BMI at the first measurement, i.e., at about one month of age, relative to discontinuers and this differences was sex-specific for males (weighted beta: 0.22; 95% CI = -0.09, 0.25). This difference flattened to the null as children grew older. We found no overtime change in BMI when antidepressant continuers were compared with unexposed. There was a small overtime increment of BMI in males born to continuers relative to initiators and the difference was largest at age 72 to 96 months of age. No such association was detected in female offspring, or when comparing initiators to the other comparators.

Conclusions: Prenatal exposure to antidepressant does not seem to negatively affect child BMI trajectories up to 8 years of age.