Site-specific characteristics of infants developing bronchopulmonary dysplasia.

Hypothesis: Site-specific variables that contribute to the pathogenesis of bronchopulmonary dysplasia (BPD) can be identified. Objectives: To evaluate the demographic, nutrition and growth characteristics of infants at risk for developing BPD at two neonatal intensive care units (NICUs: sites A and 0). Study Design: Records of 306 infants of <30 weeks gestational age (GA) who survived to at least 36 weeks postmenstrual age were retrospectively reviewed. Data were obtained for maternal and neonatal demographics, weights, total fluids, calories, carbohydrate, protein and fat intake at birth, 7, 14, 21 and 28 days of life. Results: BPD rates were not different at the two sites. No statistical differences were noted in the incidence of maternal chorioamnionitis, pregnancy-induced hypertension or use of antenatal steroids among infants who developed BPD (n = 169) and those who did not (n = 137). White race, birth weight, respiratory distress syndrome requiring surfactant, sepsis and patent ductus arteriosus were significantly associated (all P≤0.03) with BPD. After controlling for significant confounding variables, infants who developed BPD had significantly (P<0.001) less weight gain, received less calories and fat in the first postnatal month. In the 26 to 28 weeks GA group, the odds of getting BPD were 5.4 (95%CI: 1.4 to 21.3) times greater for site A than site 0 (P = 0.017). Conclusion: Our analysis suggests that while some decrease in BPD can be achieved by focusing on ventilation/oxygen use, this approach is unlikely to impact on the youngest infants.