Antenatal corticosteroids prior to 24 weeks' gestation and neonatal outcome of extremely low birth weight infants.

We sought to determine if antenatal corticosteroid treatment administered prior to 24 weeks' gestation influences neonatal morbidity and mortality in extremely low-birth-weight infants. A retrospective review was performed of all singleton pregnancies treated with one complete course of antenatal corticosteroids prior to 24 weeks' gestation and delivered between 23(0)/(7) and 25(6)/(7) weeks. These infants were compared with similar gestational-age controls. There were no differences in gender, race, birth weight, and gestational age between the groups. Infants exposed to antenatal corticosteroids had lower mortality (29.3% versus 62.9%, P = 0.001) and grade 3 or 4 intraventricular hemorrhage (IVH; 16.7% versus 36%, P < 0.05; relative risk [RR]: 2.16). Grade 3 and 4 IVH was associated with significantly lower survival probability as compared with no IVH or grade 1 and 2 IVH (P < 0.001, RR: 10.6, 95% confidence interval [CI]: 4.4 to 25.6). Antenatal steroid exposure was associated with a 62% decrease in the hazard rate compare with those who did not receive antenatal steroids after adjusting for IVH grade (Cox proportional hazard model, hazard ratio 0.38, 95% CI: 0.152 to 0.957, P = 0.04). The rates of premature rupture of membranes and chorioamnionitis were higher for infants exposed to antenatal corticosteroids. Exposure to a single course of antenatal corticosteroids prior to 24 weeks' gestation was associated with reduction of the risk of severe IVH and neonatal mortality for extremely low-birth-weight infants.