Antenatal corticosteroid therapy in premature infants.

OBJECTIVE: The objective was to examine the effect of antenatal corticosteroid treatment on premature infants, with special attention to any possible adverse effects on neonatal outcome.

METHODS: A retrospective chart review of all singleton and multiple pregnancies delivered in our perinatal center between 1991 and 1999, who had a birth weight of < or =1,500 g and who were subsequently admitted to our neonatal intensive care unit. Three hundred and sixty-five infants were included in the study and divided into two groups. One group had a gestational age below 28 weeks (< or =196 days) and one group was 28 weeks (>196 days) onward.

RESULTS: Antenatal corticosteroid therapy reduced the duration of mechanical ventilation, the need for supplementary oxygen, and the need for exogenous surfactant in neonates born at >196 days's gestation (p<0.05). Corticosteroid treatment seemed to benefit the respiratory distress syndrome (RDS; p=0.051) in this group. There were less cases of necrotizing enterocolitis and neonatal death in the group with corticosteroid treatment (p<0.05). Before 28 weeks' gestation, all parameters that were examined (e.g., duration of mechanical ventilation, need for supplemental oxygen, need for exogenous surfactant, RDS) showed no significant differences between those pregnancies pre-treated with corticosteroids or those not treated with corticosteroids. There was no adverse effect of corticosteroids on chorioamnionitis and early onset sepsis in pregnancies with a premature rupture of the membranes. Repeated corticosteroid treatment had no effect on birth weight, but did not improve neonatal outcome either. The interval between last corticosteroid treatment and delivery had no influence on RDS. There was no effect of corticosteroids on periventricular leukomalacia and intraventricular hemorrhage. Regression analysis showed a higher risk of severe RDS in multiple gestations.

CONCLUSION: Antenatal betamethasone treatment reduces perinatal morbidity and mortality after 28 weeks' gestation. We found no adverse effects and also no benefit of repetitive corticosteroid treatment. The interval between last corticosteroid treatment and delivery did not influence the incidence of RDS. Dose, timing, and rate of antenatal corticosteroids should be reconsidered in multiple gestations.