Objective: To examine the neurosensory and cognitive status of extremely low-birth-weight (ELBW; < 1,000 g) children born from January 1, 1992, through December 31, 1995, and to identify the significant predictors of outcome.
Design: An inception cohort of ELBW infants admitted to the neonatal intensive care unit (NICU) and observed to 20 months' corrected age.
Setting: A tertiary level urban NICU and follow-up clinic at a university hospital.
Population: Of 333 ELBW infants without major congenital malformations admitted to the NICU, 241 (72%) survived to 20 months' corrected age. We studied 221 children (92%) at a mean of 20 months' corrected age. The mean birth weight was 813 g; mean gestational age, 26.4 weeks.
Main outcome measures: Assessments of cognitive and neurosensory development.
Results: Major neurosensory abnormality was present in 54 children (24%), including 33 (15%) with cerebral palsy, 20 (9%) with deafness, and 2 (1%) with blindness. The mean (+/- SD) Bayley-Mental Developmental Index (MDI) score was 74.7 +/- 17. Ninety-two children (42%) had a subnormal MDI score (<70). Neurodevelopmental impairment (neurosensory abnormality and/or MDI score <70) was present in 105 children (48%). Multiple stepwise logistic regression analysis that considered sex, social risk, birth weight, and neonatal risk factors revealed significant predictors of a subnormal MDI score to be male sex (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.52-4.92), social risk (OR, 1.48; 95% CI, 1.09-2.00), and chronic lung disease (OR, 2.18; 95% CI, 1.20-3.94). Predictors of neurologic abnormality were a severely abnormal finding on cerebral ultrasound (OR, 8.09; 95% CI, 3.69-17.71) and chronic lung disease (OR, 2.46; 95% CI, 1.12-5.40); predictors of deafness were male sex (OR, 2.79; 95% CI, 1.02-7.62), sepsis (OR, 3.15; 95% CI, 1.05-9.48), and jaundice (maximal bilirubin level, >171 micromol/L [>10 mg/dL]) (OR, 4.80; 95% CI, 1.46-15.73).
Conclusion: There is an urgent need for research into the etiology and prevention of neonatal morbidity.