[Antenatal administration of glucocorticosteroids in threatened preterm birth].

The administration of glucocorticosteroids to pregnant women results in a striking decrease of neonatal morbidity and mortality in premature infants. A single course of steroids--24 mg of betamethasone or dexamethasone, given in 2 to 4 doses--does not seem to result in long-term adverse effects, although relatively few follow-up studies have been carried out. However, betamethasone causes a temporary--yet considerable--reduction in fetal heart rate variation as well as in fetal breathing and body movements. Familiarity with this phenomenon prevents unnecessary medical intervention (because of presumed fetal distress). Although the use of glucocorticosteroids was for a long time limited due to concerns about negative adverse effects, it has recently become common practice to repeat the courses weekly in the case of a persistent risk of premature birth. However, in contrast to the single course, there is no evidence that repeating a corticosteroid course improves the effectiveness of the treatment. (Long-term) adverse effects are probably dose dependent. The repetition of corticosteroids courses must therefore be advised against for the time being, unless this takes place within the framework of a randomised study.