Plasma levels of FSH and LH in patients with gonadal dysgenesis during sequential estrogen and progestogen therapy.

We describe the plasma levels of FSH and LH in ten patients with gonadal dysgenesis during treatment with a low dosage sequential estrogen-progestogen preparation. The daily dose of mestranol ranged from 12.5--50 microgram. Norethisterone was administered from day 16 onwards, the dose ranging between 0.75 and 1.5 mg. It was shown that 25 microgram mestranol was effective in lowering the elevated FSH levels significantly (alpha < 0.001). LH levels remained unaffected. The combination of 25 microgram mestranol and 1 mg norethisterone produced an increase of FSH and LH within 12 h, maximum levels being reached within 36 h after which there was a progressive decline. Low doses of estrogen and progestogen appeared capable of evoking physiological hypothalamic and pituitary responses in patients with gonadal dysgenesis. The doses employed were sufficient to induce breast development, growth of sexual hair, and withdrawal bleeding and were probably not high enough to induce rapid bone maturation and consequent stunting of growth.