Neonatal morbidities None Single morbidity BPD Brain injury Severe ROP Overall 2 Morbidities BPD+severe ROP BPD+severe PNAC Brain injury +severe ROP Severe ROP +severe PNAC Overall 3 Morbidities BPD+severe ROP+severe PNAC Brain injury+severe ROP+severe PNAC Overall 4 Morbidities Observed data No/Total (%) 2/23 (9) 2/6 (33) 7/11 (64) 9/22 (41) 18/39 (46) 2/3 (67) 2/3 (67) 4/5 (80) 1/2 (50) 9/13 (69) 3/3 (100) 1/1 (100) 4/4 (100) 1/1 (100) Abbreviations: BPD, bronchopulmonary dysplasia; ROP, retinopathy of prematurity; PNAC, parenteral nutrition associated cholestasis Fig. 1. Probability of poor outcome in the study infants with 0, 1, 2, 3 and all 4 neonatal morbidities. Observed rates of poor outcome between 18-24 months of corrected age. Solid line indicates predictions based on the fitted morbidity count model; dotted line (←), the overall probability of a poor outcome between 18-24 month of corrected age (43%). hypertension, acidosis, hypoxia, hypercapnia, anemia, neutropenia), as in the Score for Neonatal Acute Physiology (SNAP)9), or clinical parameters (gestational age, birth weight, anomalies, acidosis, FiO2), as in the Clinical Risk Index for Babies (CRIB)10). CRIB includes six parameters collected in the first 12 hour after birth, and SNAP has 26 variables collected in the first 24 hours. While these risk scoring systems may provide prognostic information for mortality, objective risk scores provide similar predictability when compared with the clinical judgment of experienced neonatologists based on birth weight, illness severity, low Apgar score, and therapeutic requirements9-13). Furthermore, such scores may not be useful for predicting long term outcome in survivors because their predictability is confused by the ongoing influence of neonatal morbidities during prolonged hospitalization8, 13, 15). BPD has been associated with low psychomotor development index scores and neurologic abnormalities including CP, poor mental development, blindness and late death. Frequent episodes of hypoxia secondary to airway constriction, poor caloric intake due to prolonged ventilation, frequent respiratory diseases, increase of the use of corticosteroid after birth, accompanying diseases such as ischemic encephalopathy, PVL, and IVH in BPD survivors could be causative factors in developmental delay14, 15). Severe brain injury is associated with poorer intellectual outcome. Severe IVH (grade III or IV), progressive hydrocephalus requiring ventricular peritoneal shunting, intraparenchymal hemorrhage, and extensive PVL are each independently associated with a poor prognosis (CP and abnormal psychomotor, or cognitive outcome) while the majority of infants with grade I or II IVH have normal neurodevelopmental outcome15, 16). ROP is also associated with later visual impairment and functional disability17). However, the clinical usefulness of each of these morbidities in predicting outcome is limited8). Up to 30% of ELBW infants with 698 Kyo Yeon Koo, et al. • Long term outcome in ELBW infants Table 5. Observed and Predicted Poor Outcome at 18-24 Months of Corrected Age in the Case of Combined Neonatal Morbidities A B Fig. 2. Probability of poor outcome by morbidity count, stratified by birth weight (A) and gestational age (B). Observed rates of poor outcome. Dotted lines (←) indicate the overall probability of a poor 18-24 month outcome (43%).