Antenatal corticosteroids: the controversy continues

Abstract

Purpose of review Maternal administration of glucocorticoids remains the mainstay of perinatal medicine for the fetus at risk of premature delivery. The reductions of severity of respiratory distress syndrome, incidence of intraventricular hemorrhage, and neonatal death have all been well documented. Findings from both experimental studies in animals as well as clinical investigation in humans have raised issues of concern and controversy. These include the use of repetitive courses of corticosteroids. Questions have been raised regarding the postnatal neurobehavioral and prenatal cardiovascular responses to corticosteroids. The purpose of this review is to address the current data pertaining to these controversies. Recent findings Animal studies reflect the concerns of the use of multiple courses of steroids with alterations of brain growth and histology. Human data suggest that multiple courses of corticosteroids might reduce the risk of respiratory distress syndrome, but at the expense of alterations of lung architecture. There are concerns about decreased somatic and head size. Neurobehavioral abnormalities are more frequently seen in children exposed to multiple courses. In growth-restricted fetuses with evidence of placental dysfunction, there may be a risk of sudden in-utero decompensation. Summary Repetitive courses of corticosteroids have deleterious effects with little improvement in neonatal outcome. A ‘rescue dose’ given to a fetus previously yet remotely treated may be of some benefit. Animal studies suggest acute vascular changes with maternal steroids. This has not been consistently borne out with the indirect assessment using Doppler in the human. A select group of severely growth restricted fetuses with umbilical artery absent end diastolic flow may actually deteriorate with maternal corticosteroids.