[Benefits and risks of antenatal corticosteroids].

Antenatal administration of a single course of corticosteroids before 34 weeks of gestation is associated in the neonatal period with a significant reduction of respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC) and death, and possibly in childhood with a reduction of cerebral palsy and increased psychomotor development index and intact survival. However, this treatment could be associated with insulin resistance in adulthood and with an increase in mental and behavioural disorders as well as more infections in childhood when birth finally occurs at term. Because of a favourable benefit/risk ratio, antenatal administration of a single course of corticosteroids is recommended for women at risk of preterm delivery before 34 weeks. Repeated antenatal corticosteroid administration is associated in the neonatal period with respiratory benefits but dose-dependent decreased birth weight and, in childhood, with possible neurological impairment. Therefore, this strategy is not recommended. There are two possible strategies for improving the benefit/risk ratio of treatment: reducing the dose or improving the timing of administration. Although it was not possible in a French trial to demonstrate the non-inferiority of a 50% dose reduction on the occurrence of severe RDS, survival without severe neonatal morbidity after half-dose was identical to that after full-dose. The results of further trials and follow-up of these children are therefore required before any conclusions can be drawn about dose reduction. Strategies to improve the timing of treatment have never been evaluated. In conclusion, antenatal corticosteroid administration is recommended to every woman at risk of preterm delivery before 34 weeks of gestation. Strategies aimed at improving the benefit/risk ratio of this treatment are still being evaluated.