The effects of the time interval from antenatal corticosteroid exposure to delivery on neonatal outcome of very low birth weight infants.

Objective: The purpose of this study was to determine whether the interval between antenatal steroid exposure and delivery influences neonatal outcome in very low birth weight infants.

Study Design: A retrospective review was performed of all live-born singleton infants who weighed between 500 and 1500 g and who were exposed to a partial course (1 dose) or a complete course (2 12-mg doses of betamethasone given 24 hours apart) of antenatal corticosteroids. Infants were divided into 4 groups, depending on the interval between the first dose of antenatal corticosteroids and delivery (<24 hours, between 24 and 48 hours, between 48 hours and 7 days, and >7 days). Logistic regression was used to control for differences between the 4 groups.

Results: Three hundred twenty-five singleton deliveries were reviewed. Gestational age at delivery and birth weight were similar for all 4 groups. The babies in the last group were treated with antenatal corticosteroids at a slightly earlier gestational age. There was no statistical difference between the groups with respect to respiratory distress syndrome treated with surfactant, intraventricular hemorrhage, necrotizing enterocolitis, and deaths.

Conclusion: In infants who weighed 500 to 1500 g, the time interval between exposure to antenatal corticosteroids and delivery does not appear to affect neonatal outcome. Further studies should evaluate the effects of antenatal corticosteroids and the effects of the interval from exposure to delivery in very low birth weight infants.