Patent ductus arteriosus and the risk of bronchopulmonary dysplasia-associated pulmonary hypertension.

In our study, preterm infants (<28 weeks' gestation) with bronchopulmonary dysplasia (BPD) had a 15% incidence of pulmonary hypertension (PH) beyond 36 weeks' postmenstrual age as a comorbidity. Moderate/large patent ductus arteriosus (PDA) shunts increased the risk of flow-associated PH when present beyond 36 weeks. Although months of prolonged PDA exposure can cause pulmonary vascular remodeling and pulmonary vascular disease (PVD) in term infants with PDA-congenital heart disease, we found no echocardiographic evidence for an association between the duration of PDA exposure and the incidence of late PVD during the neonatal hospitalization in preterm infants with BPD.