Fetal endocrine therapy for congenital adrenal hyperplasia should not be done.

Prenatal treatment of congenital adrenal hyperplasia by administering dexamethasone to a woman presumed to be carrying an at-risk fetus remains a controversial experimental treatment. Review of data from animal experimentation and human trials indicates that dexamethasone cannot be considered safe for the fetus. In animals, prenatal dexamethasone decreases birth weight, affects renal, pancreatic beta cell and brain development, increases anxiety and predisposes to adult hypertension and hyperglycemia. In human studies, prenatal dexamethasone is associated with orofacial clefts, decreased birth weight, poorer verbal working memory, and poorer self-perception of scholastic and social competence. Numerous medical societies have cautioned that prenatal treatment of adrenal hyperplasia with dexamethasone is not appropriate for routine clinical practice and should only be done in Institutional Review Board approved, prospective clinical research settings with written informed consent. The data indicate that this treatment is inconsistent with the classic medical ethical maxim to 'first do no harm'.