What is the first-line treatment for at-risk pregnancies affected by Congenital Adrenal Hyperplasia?

In at-risk pregnancies affected by Congenital Adrenal Hyperplasia (CAH), the first-line treatment is dexamethasone, which is a corticosteroid. The purpose of this treatment is to reduce excess adrenal androgens produced due to the underlying enzymatic deficiency in CAH. By administering dexamethasone to the mother during pregnancy, it helps prevent virilization of a female fetus who may be genetically affected by the condition.

Dexamethasone works by suppressing the adrenal glands' steroid production, leading to a decrease in androgens. This anticipatory treatment is crucial, as it can mitigate the impact of the prenatal exposure to high levels of androgens, potentially allowing for normal development of the female genitalia.

Other medications, such as hydrocortisone, fludrocortisone, and prednisone, do not serve the same function as dexamethasone in the context of preventing fetal virilization. Hydrocortisone and prednisone are used to manage cortisol levels in CAH patients but are not as effective in specifically addressing the fetal risks associated with the condition when the mother is pregnant. Fludrocortisone is primarily a mineralocorticoid and is not typically utilized for