Effect of severe neonatal morbidities on long term outcome in extremely low birthweight infants

Purpose: To assess the validity of individual and combined prognostic effects of severe bronchopulmonary dysplasia (BPD), brain injury, retinopathy of prematurity (ROP), and parenteral nutrition associated cholestasis(PNAC). Methods: We retrospectively analyzed the medical records of 80 extremely low birthweight (ELBW) infants admitted to the neonatal intensive care unit (NICU) of the Severance Children's Hospital, and who survived to a postmenstrual age of 36 weeks. We analyzed the relationship between 4 neonatal morbidities (severe BPD, severe brain injury, severe ROP, and severe PNAC) and poor outcome. Poor outcome indicated death after a postmenstrual age of 36 weeks or survival with neurosensory impairment (cerebral palsy, delayed development, hearing loss, or blindness) between 18 and 24 months of corrected age. Results: Each neonatal morbidity correlated with poor outcome on univariate analysis. Multiple logistic regression analysis revealed that the odds ratios (OR) were 4.9 (95% confidence interval [CI], 1.0-22.6; $P$=0.044) for severe BPD, 13.2 (3.0-57.3; $P$<.001) for severe brain injury, 5.3 (1.6-18.1; $P$=0.007) for severe ROP, and 3.4 (0.5-22.7; $P$=0.215) for severe PNAC. Severe BPD, brain injury, and ROP were significantly correlated with poor outcome, but not severe PNAC. By increasing the morbidity count, the rate of poor outcome was significantly increased (OR 5.2; 95% CI, 2.2-11.9; $P$<.001). In infants free of the above-mentioned morbidities, the rate of poor outcome was 9%, while the corresponding rates in infants with 1, 2, and more than 3 neonatal morbidities were 46%, 69%, and 100%, respectively. Conclusion: In ELBW infants 3 common neonatal mornidifies, severe BPD, brain injury and ROP, strongly predicts the risk of poor outcome.