OBJECTIVE:Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome of late-preterm and full-term infants associated with failure of the normal fetal-to-neonatal circulatory transition. This study was designed to test the hypothesis that risk for PPHN is increased after antenatal exposure to nonsteroidal antiinflammatory drugs (NSAIDs), with particular emphasis on late gestational exposures.METHODS:Between 1998 and 2003, we interviewed 377 women whose infants had PPHN and 836 control mothers of infants matched to cases by hospital and birth date. Interviews captured information on prescription and over-the-counter medication use in pregnancy as well as a variety of potential confounding factors. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for third-trimester maternal NSAID use were estimated by using multivariate conditional logistic regression.RESULTS:During the third trimester of gestation, 33 infants (8.8%) with PPHN were exposed to any NSAID compared with 80 (9.6%) controls (OR 0.8; 95% CI 0.5–1.3). We observed an elevated OR for PPHN risk among infants whose mothers consumed aspirin during the third-trimester; however, the lower 95% CI included the null. Neither nonaspirin NSAIDs at any time during pregnancy nor ibuprofen use during the third trimester was associated with an elevated risk of PPHN. Similarly, no association was observed between a mother’s third-trimester acetaminophen use and the occurrence of PPHN in her newborn.CONCLUSIONS:This large multicenter epidemiologic study of PPHN risk revealed no evidence to support the hypothesis that maternal consumption during pregnancy of NSAIDs overall or ibuprofen in particular is associated with PPHN risk.