Morbidities associated with patent ductus arteriosus in preterm infants. Nationwide cohort study

Purpose: To evaluate the predictive factors for the development of haemodynamically significant patent ductus arteriosus (PDA) in preterm infants and to study the morbidities associated with the treatment of PDA during the first hospitalization. Materials and methods: Data were collected from the Finnish national register of preterm infants (<32 gestational weeks) born in 2005-2013. In total, 3668 infants were included. Morbidities during the first hospitalization were analysed and compared between infants who received treatments for the closure of PDA (n=1132) and infants who received no treatment for PDA (n=2536). The results were adjusted for the duration of pregnancy, intrauterine growth pattern, antenatal steroids, delivery hospital and respiratory distress syndrome (RDS). Results: RDS and mechanical ventilation were independently associated with an increased risk of PDA requiring treatment. Medical and surgical treatments were associated with the risk of severe bronchopulmonary dysplasia (BPD). Primary surgical ligation was associated with an increased risk of severe intraventricular haemorrhage (IVH) and necrotizing enterocolitis (NEC). Medical treatment itself and also followed by surgical ligation was associated with lower mortality. Conclusion: The severity of lung disease rather than prematurity per se was associated with the development of PDA requiring therapy. Both medical and surgical therapies for PDA were associated with severe BPD, and primary surgical ligation was associated with NEC and severe IVH.