Congenital adrenal hyperplasia in pregnancy: approach depends on who is the 'patient'.

Congenital adrenal hyperplasia (CAH) is a group of autosomal-recessive disorders caused by a reduced or absent enzymatic activity at one of the stages of adrenal steroid biosynthesis. Prenatal exposure to androgens leads to external genital masculinization of the affected female child. In pregnancy, the provider may be optimizing care for the woman with CAH or targeting treatment to reduce virilization in the affected unborn child. For the affected adult woman the goals of therapy in pregnancy are to prevent adrenal insufficiency, reduce fetal exposure to androgens and glucocorticoids and to avoid damage to reconstructed genitalia. For prenatal therapy for prevention of virilization of possibly affected female children, dexamethasone is used. However, questions remain about the efficacy and safety of exposing 7/8 unaffected children in the first trimester. Prenatal treatment should only be undertaken after careful discussion with the parents of the risks and benefits in an experienced centre or as part of a research protocol.