ABSTRACT This follow-up study presents the results of the Multiple Courses of Antenatal Corticosteroids for Preterm-Birth Study, a multicenter, international, randomized, double-blind, placebo-controlled trial conducted in pregnant woman at high risk of preterm birth. The initial results of the study published in 2008 reported that multiple courses of prenatal corticosteroid therapy, given every 14 days, provided no decrease in perinatal mortality or neonatal morbidity and was associated with reduced size at birth (lower birth weights, smaller head circumferences, and shorter birth lengths), compared with a single course of prenatal corticosteroid therapy. Previous small trials suggested that this multidose regimen could provide short-term benefits with respect to reductions in the occurrence and severity of neonatal lung disease lessening the need for ventilatory support. However, this short-term benefit was offset by unfavorable long-term outcomes, such as a possible elevated risk of cerebral palsy. Moreover, there was no long-term benefit on childhood neurodevelopment. The aim of this follow-up study was to investigate the effects of repeated courses of prenatal corticosteroid therapy compared with placebo treatment on death or neurologic impairment at 18 to 24 months of age. Women in both groups received an initial treatment with a prenatal corticosteroid and remained at high risk of preterm birth. The 1858 women enrolled in the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study delivered 2304 infants eligible for the 2-year follow-up evaluation; of these infants, 2104 were monitored (1069 in the study group and 1035 in the placebo group). The primary outcome was death or neurologic impairment at 18 to 24 months of age, adjusted for gestational age at birth, with neurologic impairment defined as the presence of cerebral palsy or a cognitive delay. The secondary outcomes were anthropometric measurements of growth (height, weight, and head circumference). The data showed no statistically significant difference between the treatment groups in the risk of death or neurologic impairment (study group, 13.8% SYMBOL vs. placebo group, 13.7% SYMBOL the odds ratio was 1.001, with a 95% confidence interval of 0.75–1.30; P = 0.95). There was also no significant difference between the study group and the placebo group in mean weight (11.94 vs. 12.14 kg, P = 0.04), mean height (85.51 vs. 85.46 cm, P = 0.87), or mean head circumference (48.18 vs. 48.25 cm, P = 0.45), respectively. Symbol. No caption available. Symbol. No caption available. These findings show that repeated courses of prenatal corticosteroid therapy have no effect on survival rates or the presence of neurologic impairment at 18 to 24 months of age compared with a single course of prenatal corticosteroid therapy.