The aim of this study was to determine whether improved survival of extremely low birth weight infants (ELBWI) was associated with decreased neurodevelopmental disability later in life, and also to identify the factors influencing this disability.

ELBWI admitted to the neonatal intensive care unit of Samsung Medical Center, survived, and followed up until the corrected age of 18 months were enrolled. They were divided into two groups according to admission time: period I (1994-1999, n=36) and period II (2000-2004, n=98). Clinical data were collected retrospectively from the medical records.

Survival rates increased from 60.0% to 74.7%, cerebral palsy rates decreased from 22.2% to 8.2% and catch-up growth rate increased from 25.0% to 51.0% during period I and II. Despite less gestational age and birth weight, ELBWI during period II had less periventricular leukomalacia (PVL), sepsis and bronchopulmonary dysplasia compared to period I. The highest risk factors for cerebral palsy were intraventricular hemorrhage (IVH) (≥Grade III), failure of catch-up growth and PVL.

In summary, improved viability was associated with decreased neurodevelopmental disability in ELBWI. Improved neonatal care with resultant decrease in PVL and IVH, and better nutritional support seem to be primarily responsible for this improved outcome.