Mid- and long-term outcome of extremely low birth weight (ELBW) infants: an analysis of prognostic factors.

OBJECTIVE: To evaluate morbidity and long-term neurological outcome in a group of extremely low birth weight infants (ELBW; <1000 g) and to correlate the neurological outcome in a small group of intrauterine growth retarded (IUGR) infants with Doppler indices in the umbilical artery.

METHODS: One hundred and eighty-three live births with birth weight <1000 g and gestational age < or=34 weeks were included in the study. Neonatal mortality and morbidity were evaluated. At 24 months of corrected age an evaluation of the neurological development of the children was made by pediatric neuropsychiatrists. The children were classified as: normal, with minor neurological sequelae, and with major neurological sequelae. The evaluation of umbilical artery velocimetry was applied to 84 fetuses presenting with IUGR and the velocimetric patterns were correlated with neurological outcome.

RESULTS: In the 183 infants discharged from the Department of Neonatology, respiratory distress syndrome (RDS) was the most frequent pathology (76.6%); less frequent were bronchopulmonary dysplasia (BPD; 19.5%), patent ductus arteriosus (PDA; 29.7%) and necrotizing enterocolitis (NEC; 5.5%). Retinopathy of prematurity (ROP) affected 34 children (26.6%), and 14.8% of the children developed intraventricular hemorrhage (IVH) and 14.1% periventricular leukomalacia (PVL). Out of the 183 infants included in the study, 107 had a neurological assessment at two years: 22 (20.6%) suffered from severe neurological sequelae, 20 (18.7%) from minor neurological sequelae, and 65 (60.7%) had a normal neurological development. In 84 IUGR fetuses a Doppler evaluation of the umbilical artery was performed: the incidence of neurologically normal children was 67% in the group with normal umbilical velocimetry, 93% in the group with increased umbilical resistances, and 59% in those with absent or reversed end-diastolic velocity (ARED).

CONCLUSIONS: This study, confirms that an extremely low birth weight implies a high risk of perinatal mortality and neonatal morbidity, but that the most significant variable that can be correlated to the long-term neurological outcome is the gestational age.