ObjectiveTo assess the contribution of the severity of bronchopulmonary dysplasia (BPD) and the time point of its diagnosis to the prediction of neurodevelopmental impairment (NDI) at corrected age of 2 years in preterm infants.DesignRetrospective cohort study.SettingLevel-III perinatal centre.Patients and outcome measuresInfants born in 2000–2013 with gestational age <30 weeks. BPD was defined as FiO2 >21% for ≥28 days and its severity classified as mild, FiO2=21%; moderate, FiO2 <30% and severe, FiO2 ≥30% and/or positive pressure support. We applied these criteria at two time points: 36 and 40 weeks’ postmenstrual age (PMA). Multivariable regression models were used to estimate the association (OR (95% CI)) between BPD characteristics and NDI defined as cognitive or motor development score <2 SD; severe cerebral palsy; deafness and blindness.ResultsOf 610 (81% of cohort) children assessed at 2 years, 357 (58%) had BPD and 98 (16%) had NDI. Neither FiO2 >21% for ≥28 days nor mild or moderate BPD at either 36 or 40 weeks’ PMA was associated with NDI, but severe BPD was (at 36 weeks’ PMA 5.6 (2.0 to 16.0) and at 40 weeks’ PMA 16.6 (4.6 to 59.9)). Infants with severe BPD at both 36 and 40 weeks’ PMA had lower mental (mean difference −11.4 (−18.5 to −4.3), −25.7(−35.9 to −15.5), respectively) and motor (−7.8 (−14.9 to −0.6), −20.1(−30.7 to −9.5), respectively), developmental scores than infants without BPD.ConclusionIn this cohort, severe BPD was a better independent predictor of NDI at 2 years than mild or moderate BPD. BPD diagnosed at 40 weeks’ PMA might allow better identification of infants at highest risk for NDI.

In preterm babies requiring surgical patent ductus arteriosus closure, longer respiration times reflect a delay while attempting medical treatment, but respiration time is equally short between groups after shunt elimination. Medical treatment, although a valid first option, is likely to fail with larger patent ductus arteriosus diameters and lower birth weights. Unwarranted assisted respiration and corresponding hospital stay might be shortened by earlier surgical referral for patent ductus arteriosus closure in preterm babies with a patent ductus arteriosus index of greater than 9 mm2/kg.