Background: Though prenatal antidepressant exposure has been associated with adverse developmental outcomes, the extent to which the effects are due to prenatal drug exposure or underlying maternal mood disturbances is unclear.
Methods: This was a population-based retrospective cohort study using administrative data from British Columbia, Canada (n = 94,712). Analyses were designed to remove confounding effects of prenatal antidepressant exposure from maternal mood. First, children prenatally exposed to antidepressants were matched to unexposed children using high-dimensional propensity scores (HDPS). Second, children whose mothers had used antidepressants throughout pregnancy were compared against those whose mothers discontinued treatment.
Results: In all, 3.87% (n = 3661) of children in the overall study population were prenatally exposed to antidepressants. In both analyses, we report increased odds for lower levels of physical independence (HDPS: OR, 1.14; 95% CI, 1.00-1.30; continuers/discontinuers: OR, 1.14; 95% CI, 0.99-1.32), and higher levels of anxious behaviors (HDPS: OR, 1.30; 95% CI, 1.01-1.66; continuers/discontinuers: OR, 1.32; 95% CI, 1.01-1.72) associated with antidepressant use in pregnancy. All other relationships were not significant using these methods.
Conclusions: Prenatal antidepressant exposure was selectively associated with worse anxious behaviors and physical independence at kindergarten age, with no effects on other developmental domains. Effects are also likely attributable to maternal mental illness severity or other unmeasured confounding factors.
Impact: Selective associations between prenatal antidepressant exposure and children's anxiety and physical independence at kindergarten were identified, with no impact on other developmental domains. Contradictory reports have emerged regarding the association of adverse child outcomes with prenatal antidepressant exposure. These inconsistencies may be due to differences in control for confounding. Effects of prenatal antidepressant exposure on anxious behaviors and physical independence are likely also attributable to severity of underlying maternal mood disorders, highlighting the importance of maternal mental health for developmental health.