Antenatal glucocorticoid treatment of women at risk of preterm delivery between 24 and 34 weeks' gestation has been the standard of care since 1994. Recent information supports its use with preterm prolonged rupture of membranes, in very early gestations in which neonatal survival will be attempted, and in women with preeclampsia. Many women who deliver before 30 weeks' gestation have chronic silent chorioamnionitis, which does not seem to be a contraindication to antenatal glucocorticoid therapy. The preferred antenatal treatment is a short- and long-acting betamethasone combination given as 12-mg maternal injections at the identification of preterm labor and 24 hours later. Repeated courses of antenatal glucocorticoids given at 7- to 10-day intervals if preterm delivery does not occur are not indicated. Antenatal glucocorticoid therapy is very effective, and no adverse effects of a single treatment course have been identified.