Treatment in utero of potentially affected CAH patients is feasible by administering dexamethasone to the mother starting from the first weeks of pregnancy, with the aim of containing adrenal hyperandrogenism by reducing ACTH hypersecretion and avoiding genital masculinization in the CYP21A2-D female fetuses (2). The gene discussed is CYP21A2; the disease is congenital adrenal hyperplasia.