[Prenatal corticotherapy and acceleration of fetal maturation. I. Experimental and pharmacological data]

Data from numerous experimental studies clearly indicate that endogenous corticosteroids physiologically act on the fetal lung maturation. There are also convincing experimental data demonstrating that exogenous corticosteroids stimulate phospholipids biosynthesis, induce the surfactant specific protein genes expression, and improve the lung biophysical properties. The first report of a clinical beneficial effect derived from these experimental observations is due to Liggins and Howie who demonstrated that prenatal corticosteroid treatment significantly reduces the incidence of respiratory distress syndrome and the mortality among preterm neonates. Fluorinated corticosteroids (dexamethasone, betamethasone) are the only efficient corticosteroids, with the advantage of a low mineralocorticoid activity. After a single course, they do not inhibit postnatal stress adrenal response; however, repeated courses may induce adrenal depression if a stressing event occurs after birth.