Recovery of glucocorticoid-related loss of synaptic density in the fetal sheep brain at 0.75 of gestation.

Antenatal glucocorticoids routinely used to accelerate fetal lung maturation in human pregnancy at risk of preterm delivery decrease synaptic density and complex electrocortical activity in the fetal sheep brain at 0.87 gestation. We examined whether the effects of betamethasone on synaptic density depend on maturation of hypothalamo-pituitary-adrenal (HPA) axis and whether these effects are reversible.