ABSTRACT
Evolution of modern neonatology has dramatically increased the number of survivors of extremely low birth weight (ELBW) infants (birth weight < 1000 g) and extremely low gestational age (ELGA) neonates (postconceptional age < 28 weeks) (1-3). Of interest is that most recently, emerging reports for ELBW and ELGA neonates suggest improving neurodevelopmental outcomes in developed countries, including declining rates of cerebral palsy at the turn of the century (4-6). An examination of which factors may have contributed to the improved outcome include common use of antenatal corticosteroids and surfactant therapy, drastic reduction in the use of postnatal corticosteroids, less time on ventilator, minimizing nosocomial infections, and regionalization to tertiary care centers with high level and volume of care (7,8). Although the rates of mortality have declined, the incidence of bronchopulmonary dysplasia (BPD) has remained almost unchanged, affecting approximately 22% to 23% of ELBW infants, and around 50% in the group of the most premature infants. The improved survival rates of ELBW infants, particularly those weighing less than 1000 g, may explain, in part, the consistent rate of BPD (1). Transient episodes of oxygen desaturation followed by hyperoxic peaks during mechanical ventilation or on continuous positive airway pressure (CPAP), high rates of nosocomial sepsis, poor growth and nutrition, and separation from the mother associated with prolonged hospitalization, altogether may be important factors contributing to unfavorable outcome in these babies (8). In addition, more babies of the smallest gestational age (<25 weeks) may survive and contribute to poorer outcome in total of this group of babies.
