sB7-H3 (day 7), IL-18 (day 14), NCIS, electrolyte disturbance, hs-PDA, and the age that infants achieved 120 kcal/kg.d via enteral feeding ≥40 days after birth were brought into the stepwise multiple logistic regression analysis to yeild a predictive model for BPD development. The gene discussed is IL18; the disease is Patent ductus arteriosus.