The incidence of pulmonary hypertension and the association with bronchopulmonary dysplasia in preterm infants of extremely low gestational age

Background: Pulmonary hypertension (PH) occurs in ~25% of infants with moderate-tosevere bronchopulmonary dysplasia (BPD) and is associated with substantial morbidity and mortality. The American Heart Association and American Thoracic Society recommend routine echocardiographic screening for PH in preterm infants with BPD at 36 weeks’ postmenstrual age (PMA), yet the true incidence remains unclear owing to non-uniform diagnostic criteria. Emerging evidence suggests a potential role for earlier screening. Objectives: (i) to determine the incidence of pulmonary hypertension (PH) and bronchopulmonary dysplasia (BPD) in preterm infants of extremely low gestational age