A comprehensive analysis of clinical variables for severe bronchopulmonary dysplasia in extremely preterm infants

Background: Identifying clinical risk factors that may forecast the development of severe bronchopulmonary dysplasia (BPD) in very and extremely premature infants can assist clinicians in implementing early interventions to reduce long-term morbidity and mortality rates. Methods: A cohort study of enrolled preterm neonates born before the gestational age (GA) of 32 weeks was performed between May 2018 and January 2022. Clinical parameters and comorbidities were gathered retrospectively from medical records and compared among different BPD severity levels based on the diagnostic definition of the 2019 National Institute of Child Health and Human Development criteria. Random forest models were used to rank the importance of clinical variables independently for severe BPD development. Results: A total of 134 preterm infants were enrolled and then divided into three groups based on their BPD severity. Unlike infants with no or mild BPD, the GA, birth weight, and Apgar score at 5 min were considerably lower in preterm infants with severe BPD (P < 0.001). Subgroup analysis of preterm infants born before GA 28 weeks revealed that only birth weight was significantly lower in those with severe BPD (P = 0.001). Furthermore, sepsis rates were significantly higher in extremely preterm infants with severe BPD (P < 0.001). Using random forest analysis, sepsis, birth weight, and patent ductus arteriosus (PDA) appeared to have the highest importance for severe BPD in extremely premature infants. Conclusion: Lower birth weight, sepsis, and the presence of PDA all play important roles in the development of severe BPD in extremely preterm infants.