Prenatal exposure to non-steroidal anti-inflammatory drugs (NSAIDs) and neurodevelopmental outcomes in children

Purpose: Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used during pregnancy. Findings that prenatal NSAID exposure may affect offspring neurodevelopment have been inconsistent. We investigated the effect of prenatal NSAID exposure on childhood neurodevelopment and explored the susceptibility of our effect estimates to forms of bias via negative exposure, negative outcome, and multi-informant analyses. Methods: In a cohort of pregnant women (n=6876), perinatal NSAID use was assessed by prescriptions and self-report. Primary neurodevelopmental outcomes included attention problems using maternal reports at 11/2, 3, and 5years. To explore potential systematic biases, we compared estimates from maternally reported attention problems to a teacher's report and a measure of nonverbal intelligence assessed at a clinic visit at age 6years; we also used NSAID use before pregnancy and somatic problems as a negative exposure and outcome, respectively. Results: Maternal reports suggested that prenatal exposure to NSAIDs was associated with more attention problems at younger ages (eg, at age 3: mean difference in attention problems score: 0.30; 95% CI 0.12, 0.48). However, no strong association with attention problems was found in the teacher report, and a similarly strong association between prenatal NSAID exposure and somatic complaints suggests residual confounding by indication likely remains. Moreover, prenatal exposure to NSAIDs was not associated with an observed measure of IQ (mean difference in IQ score: -0.32; 95% CI: -1.82, 1.19). Conclusions: Jointly, our results suggest that the observed associations between prenatal exposure to NSAIDs and child attention problems reflect systematic biases of a null or small effect.