Antenatal steroid therapy and 5-year outcome of extremely low birth weight infants.

Over a 63-month period beginning January 1, 1977, 258 infants with birth weights of 500-999 g were born alive at one tertiary perinatal center; 170 were offered full intensive care. The mothers of 67 (39.4%) of these 170 infants had been given betamethasone antenatally to accelerate fetal lung maturation. Of the 67 infants exposed to steroids antenatally, 46 (68.7%) survived their primary hospitalization, compared with 43 (41.7%) of the 103 infants who had not been exposed to steroids. This difference is highly significant (chi 2 = 10.7; P less than .005) but is biased because infants in the steroid group had a better prognosis. After adjustment for discrepancies in birth weight and gestational age and other confounding obstetric variables, survival in the steroid group remained substantially higher (relative odds of survival 1.85, 95% confidence intervals 1.16-2.86; P = .006). The improvements in survival were not at the expense of increased rates of chronic ill health or impairments of growth neurodevelopment up to at least 5 years of age. For extremely immature and extremely low birth weight infants, steroids are rarely contraindicated on fetal grounds.