Classic congenital adrenal hyperplasia and its impact on reproduction

Women with classic congenital adrenal hyperplasia (CAH) can suffer from impaired fertility rates as a result of increased androgen secretion or impaired sex steroid production. In virilizing CAH forms, such as 21-hydroxylase and 11β-hydroxylase deficiency, the low reported pregnancy rate is mainly secondary to a diminished desire to conceive. Optimal glucocorticoid and/or mineralocorticoid replacement, sufficient to normalize androgen and P levels in the follicular phase, allows natural conception in most cases. The remaining CAH forms exemplified by StAR, P450scc, P450-oxidoreductase, and 17α-hydroxylase/17-20 lyase deficiencies are associated with impaired sex steroid production. Several factors are involved in the true low fertility rate in this group: folliculogenesis arrest, uterine hypoplasia, and inadequate endometrial thickness related to aberrant androgen, estrogen, and P secretion. There are several reports of successful term pregnancies achieved through controlled ovarian hyperstimulation, followed by estrogen replacement and IVF. Progress in female genitalia reconstructive surgery, individualized hormonal therapies, psychosexual evaluation, and assisted reproductive technology have improved fertility and pregnancy outcomes in women with classic CAH. Finally, successful gestational management in CAH patients requires the close coordination of care between endocrinologists and obstetricians.