Increased incidence of bronchopulmonary dysplasia after antenatal administration of indomethacin to prevent preterm labor.

The aim of this randomized study was to compare the neonatal outcome in infants who have been exposed in utero to indomethacin with that in infants exposed to a beta-adrenergic agonist, nylidrin hydrochloride. Eighty pregnant women threatened with preterm labor between 24 and 34 weeks of gestation were enrolled in the study. An intravenous infusion of nylidrin or enterally administered indomethacin was given for a maximum of 72 hours. If preterm labor recurred, all parturient patients were treated with nylidrin. Indomethacin prolonged gestation significantly more than the beta-adrenergic agonist (6.6 weeks vs 4.5 weeks; p = 0.04). Ten of the forty-two infants exposed to indomethacin and 2 of the 45 infants exposed to nylidrin had bronchopulmonary dysplasia (24% vs 5%; p = 0.02). Among the 28 infants delivered within 120 hours after the start of treatment, the incidences of respiratory distress syndrome (82% vs 29%; p = 0.02), bronchopulmonary dysplasia (73% vs 6%; p = 0.0006), and necrotizing enterocolitis or focal intestinal perforation (27% vs 0%; p = 0.03) were higher among those exposed to indomethacin than among those exposed to nylidrin. We infer that administration of indomethacin to pregnant women threatened with premature labor is associated with an increased risk of bronchopulmonary dysplasia in their infants if delivery occurs early.