Supplementary Material for: Identifying Risk Factors Shared by Bronchopulmonary Dysplasia, Severe Retinopathy, and Cystic Periventricular Leukomalacia in Very Preterm Infants for Targeted Intervention

Background: Bronchopulmonary dysplasia (BPD), severe retinopathy of prematurity (sROP), and cystic periventricular leukomalacia (cPVL) are 3 major morbidities with long-term neurodevelopmental impairments in preterm infants. Objective: To investigate the strength of associations and identify key risk factors shared by BPD, sROP, and cPVL for targeted intervention. Methods: We studied the Taiwanese very-preterm-infant registry data on 3,507 infants admitted to neonatal intensive care units and discharged at postmenstrual age ≥36 weeks between 2008 and 2013. Results: Of 3,507 infants, 1,497 presented with at least 1 morbidity (26 [1.7%], 386 [25.8%], and 1,085 [72.5%] exhibited 3, 2, and 1 morbidities, respectively). BPD was strongly associated with sROP (odds ratio 5.93; 95% confidence interval 5.02–7.03), followed by cPVL (2.08; 1.63–2.64), but sROP and cPVL were weakly associated (1.59; 1.17–2.13). Most risk factors contributed to BPD, which shared risk factors with sROP and cPVL. A birth weight of < 1,000 g, male sex, and prolonged mechanical ventilation (MV) were shared by BPD and sROP, and chorioamnionitis, severe respiratory distress syndrome, and prolonged MV specifically contributed to BPD and cPVL. Prolonged MV was the single risk factor common to BPD, sROP, and cPVL. Avoiding prolonged MV reduced the risk of having at least 1 of the 3 morbidities by 37%. Conclusions: BPD and sROP were most strongly associated. Most risk factors contributed to BPD, with differentially shared effects on sROP and cPVL. Prolonged MV was the only risk factor shared by all 3 morbidities, and avoiding it potentially reduced the risk of having at least 1 of them.