Risk of preterm delivery: a single course of antenatal corticosteroids

For women at risk of delivery before 34 weeks of gestation, administration of betamethasone or dexamethasone for 24 or 36 hours reduces neonatal morbidity and mortality. In a double-blind randomised trial involving 1858 pregnant women, who received either a single course of corticosteroids or multiple courses every 14 days, no statistically significant difference in the rates of mortality and respiratory morbidity were observed during the 28 first days of life. Newborns had decreased height, weight and head circumference in the group treated every 14 days. No difference in outcome was noted at 2 years among 1047 infants whose mothers had received a single course of betamethasone or weekly treatment up to 32 weeks of gestation. Similarly, no difference in outcome was observed among 556 children whose mothers had received an initial course of betamethasone followed by regular injections of either betamethasone or placebo. However, 6 children (2.9%) exposed to repeated maternal treatment developed cerebral palsy, versus only one of the children (0.5%) exposed to a single course, indicating that repeat courses of antenatal corticosteroids might have a detrimental effect. In practice, it seems prudent to only use a single course of corticosteroids in this setting.