Acetaminophen for Patent Ductus Arteriosus and Risk of Mortality and Pulmonary Morbidity

OBJECTIVE Emerging data indicate that acetaminophen may adversely affect lung health. We examined whether acetaminophen compared with cyclooxygenase (COX) inhibitor alone for patent ductus arteriosus (PDA) is associated with mortality or respiratory morbidity in extremely preterm infants. METHODS This is a retrospective cohort study using data from the National Institute of Child Health and Human Development Neonatal Research Network. Infants were born at 22 to 28 weeks’ gestation or weighing 401 to 1000 g between 2016 and 2020 and received acetaminophen, ibuprofen, and/or indomethacin for PDA closure. The primary outcome was death or grade 2 to 3 bronchopulmonary dysplasia (BPD) at 36 weeks’ postmenstrual age. Secondary outcomes included predischarge mortality and respiratory morbidities. Risk ratios were adjusted for baseline and early postnatal factors. Additional exploratory analyses were adjusted for later postnatal covariates. RESULTS Of 1921 infants, 627 (32.6%) received acetaminophen and 1294 (67.3%) received COX inhibitor only. Multidrug therapy (42.9% vs 4.7%) and surgical or catheter PDA closure (26.5% vs 19.9%) were more common among acetaminophen-exposed infants. Death or grade 2 to 3 BPD at 36 weeks’ postmenstrual age was similar between infants treated with acetaminophen versus COX inhibitor only (57.1% vs 58.3%; adjusted relative risk aRR 0.96, 95% confidence interval CI 0.87–1.06). Acetaminophen was associated with increased risk of predischarge mortality (13.3% vs 10.0%) when adjusting for perinatal and early postnatal factors (aRR 1.42, 95% CI 1.02–1.93), but not in exploratory analyses that included later postnatal factors (aRR 1.28, 95% CI 0.91–1.82). CONCLUSIONS Treatment with acetaminophen versus COX inhibitor alone for PDA was not associated with the composite outcome of death or BPD in extremely preterm infants. Our results support further evaluation of whether acetaminophen for PDA increases mortality.