Drug of choice for pregnant female suspected of having a baby with congenital adrenal hyperplasia is
Dexamethasone
Betamethasone
Hydrocoisone
Predinsolone
Dexamethasone is very potent and highly selective glucocoicoid to be staed before 10 weeks of gestation to suppress fetal androgen production effectively It has a long duration of action and cause marked pituitary-adrenal suppression. DOC for CAH is hydrocoisone but DOC for pregnant women having baby with CAH - dexamethasone REF.Essential of medical pharmacology K D TRIPATHI 6 Edition, Page No - 283
Endocrinology