Background: Changes in survival, hospital morbidities and developmental outcome of extremely preterm infants were assessed prospectively by comparing the outcomes of two cohorts of infants born at 23-27 weeks' gestation.

Subjects: The 2 groups (all live births: 7/1/85-6/30/86, n=61 and 7/1/90-6/30/91, n=65) were similar for mean birthweight (820± 189 and 808± 174g, respectively), gestational age (25.7±1.1 and 25.4±1.3 wk), number inborn (92 and 82%) and survival to hospital discharge (44/61, 72% and 44/65, 68%). The two groups were comparable for gender, race, and maternal age, education and marital status.

Interventions: Morbidities among survivors, including durations of mechanical ventilation (38±24 and 36±21 days, respectively), supplemental oxygen (72±28 and 94±74 days) and hospitalization(88±21 and 96±20 days) did not decrease between study periods. At 4 years of age, 100% of survivors were evaluated.

Results: Three children in group 1 (7%) and six in group 2 (14%) with severe cerebral palsy and developmental delays were untestable on the McCarthy Scales of Children's Abilities. Of the remaining children, 92% of each group were neurologically intact and had similar mean IQ scores (95± 15 and 92±20).

Conclusion: Survival, early morbidity and four year outcome have not improved for extremely preterm infants born in 1985 and 1990.