Menarche and subsequent ovarian function in girls with congenital adrenal hyperplasia.

The mean age at menarche in 6 girls on treatment for congenital adrenal hyperplasia from infancy was 13.6 years (range 12.6-14.5 years). Menarche or regular menses did not occur until plasma testosterone concentrations were within normal limits. This was achieved using single daily dexamethasone, 0.25-0.75 mg/day. The potency of this glucocorticoid in suppressing adrenal steroid biosynthesis relative to cortisol is about 80:1. The onset of regular, ovulatory menstrual cycles, as judged by daily salivary progesterone profiles, was achieved within 2-3 years of menarche using this treatment regimen. Such patients have a good prognosis for normal fertility.