Single versus weekly courses of antenatal corticosteroids: evaluation of safety and efficacy.

Objective: The purpose of this study was to determine if weekly corticosteroids improve neonatal outcome without undue harm.

Study Design: Women 23 to 32 weeks receiving 1 course of corticosteroids 7 to 10 days prior were randomized to weekly betamethasone or placebo.

Results: The study was terminated by the independent data and safety monitoring committee with 495 of the anticipated 2400 patients enrolled. There was no significant reduction in the composite primary morbidity outcome (8.0% vs 9.1%, P = .67). Repeated courses significantly reduced neonatal surfactant administration (P = .02), mechanical ventilation (P = .004), CPAP (P = .05), pneumothoraces (P = .03). There was no significant difference in mean birth weight or head circumference. The repeat group had a reduction in multiples of the birth weight median by gestational age (0.88 vs 0.91) (P = .01) and more neonates weighing less than the 10th percentile (23.7 vs 15.3%, P = .02). Significant weight reductions occurred for the group receiving > or = 4 courses.

Conclusion: Repeat antenatal corticosteroids significantly reduce specific neonatal morbidities but do not improve composite neonatal outcome. This is accompanied by reduction in birth weight and increase in small for gestational age infants.