[Prenatal treatment of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. 9 treated pregnancies].

Prenatal treatment based on administration of dexamethasone to the mother during pregnancy was initiated early during nine pregnancies with a high risk of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. The purpose of this treatment was to prevent fetal virilization by reducing production of androgens by the adrenal glands. Prenatal diagnosis was achieved by comparing amniotic fluid cell HLA genotypes and more recently by subjecting trophoblasts to molecular genetic studies. Together with prenatal determination of fetal sex, this allowed to determine that only two female fetuses were affected. Efficacy of continued prenatal treatment in these two cases was good in one case and mediocre in the other. The treatment was well tolerated by the mothers and fetuses.