Congenital adrenal hyperplasia is a group of monogenic autosomal recessive disorders due to an
enzyme deficiency in
steroid biosynthesis. The most frequent form of
congenital adrenal hyperplasia is
21-hydroxylase (21-OH) deficiency, which in its severe form can cause
ambiguous genitalia in the female patient. Recent advances in molecular genetic analysis allow for prenatal diagnosis and treatment of at-risk fetuses. The objective of prenatal diagnosis and treatment of 21-OH deficiency is the prevention of prenatal
virilization in affected female infants, reducing the risks of sex misassignment and gender
confusion, and the need for corrective genital surgery. Prenatal treatment of 21-OH deficiency is effective in reducing
genital ambiguity, and short-term outcome studies of children exposed to
dexamethasone in utero indicate no significant adverse effects. However, more long-term studies of treated versus untreated pregnancies are warranted to monitor the safety of treatment and enhance our understanding of the effects of prenatal
steroid exposure to the human brain. In the first year of life, optimization of medical treatment in
salt-wasting patients is achieved by combining the lowest dose of
glucocorticoid able to suppress
androgen secretion with the normalization of
sodium balance by giving appropriate
sodium chloride supplementation.