Antenatal corticosteroid therapy to enhance fetal lung maturation in pregnancies at risk for preterm delivery is used commonly, based on the assumption that its established benefits outweigh associated risks. Corticosteroid treatment does confer some risks, particularly with respect to restricted brain growth and disordered neuronal development. These alterations have the potential for long-term effects on health. They deserve further study, and should not be undervalued. Corticosteroid therapy should be applied selectively in those situations in which the risk of preterm birth is very high and the likelihood of severe respiratory distress syndrome substantial.