Neurodevelopment of Children Prenatally Exposed to Selective Reuptake Inhibitor Antidepressants: Toronto Sibling Study

Background: The reproductive safety of selective reuptake inhibitor (SRI) antidepressants needs to be established to provide optimal control of maternal depression while protecting the fetus.

Objective: To define a child’s neurodevelopment following prenatal exposure to SRIs and to account for genetic and environmental confounders in a sibling design using the Toronto Motherisk prospective database.

Method: Intelligence and behavior of siblings prenatally exposed and unexposed to SRIs were assessed by using the Wechsler Preschool and Primary Scale of Intelligence-Third Edition, Child Behavior Checklist, and Conners Parent Rating Scale-Revised and subsequently compared. Mothers, diagnosed with depression using DSM-IV, were assessed for intelligence quotient (IQ) and for severity of depressive symptoms with the Center for Epidemiologic Studies Depression scale. Prenatal drug doses and durations of exposure, child’s age, child’s sex, birth order, severity of maternal depression symptoms, and Full Scale IQ, the primary outcome measure, of both the mother and the child were considered in the analyses.

Results: Forty-five sibling pairs (ages 3 years to 6 years 11 months, prenatally exposed and unexposed to SRIs) did not differ in their mean ± SD Full Scale IQs (103 ± 13 vs 106 ± 12; P = .30; 95% CI, −7.06 to 2.21) or rates of problematic behaviors. Significant predictor of children’s intelligence was maternal IQ (P = .043, β = 0.306). Severity of maternal depression was a significant predictor of Child Behavior Checklist Internalizing (P = .019, β = 0.366), Externalizing (P = .003, β = 0.457), and Total scores (P = .001, β = 0.494). Drug doses and durations of exposure during pregnancy did not predict any outcomes of interest in the exposed siblings.

Conclusions: SRI antidepressants were not found to be neurotoxic. Maternal depression may risk the child’s future psychopathology. The sibling design in behavioral teratology aids in separating the effects of maternal depression from those of SRIs, providing stronger evidence in clinical decision-making.