Mother with previous history of delivery a CAH child, what to do in next pregnancy in regard to steroid therapy

CAH (congenital adrenal hyperplasia) is associated with masculinisation of a female fetus caused by reduced or absent enzymatic activity at one of the stages of adrenal steroid biosynthesis. Prenatal exposure to androgens leads to external genital masculinisation of the affected female child. Since it is an autosomal recessive disorder, there is risk of recurrence. Diagnosing the fetal sex before is impoant since the problems of virilisation in girls are permanent at this stage. To prevent masculinisation of a female fetus its impoant that the changes are prevented from occurring by providing exogenous steroids during the intrauterine life itself. Protocol commonly followed - -Sta Steroids once pregnancy is diagnosed -Fetal sex is detected by CVS after 10 weeks -In case of Male fetus and unaffected female fetus , stop the Steroid -in affected females continue Dexamethasone