The impact of dosage on ovulation induction by pulsatile gonadotropin-releasing hormone (Gn-RH) in hypothalamic amenorrhea.

Ten patients with hypothalamic amenorrhea (HA) were treated to induce ovulation with i.v. pulsatile Gn-RH. Twentysix cycles were administered with doses ranging from 2.5 (A; no. = 10) to 5 (B; no. = 13) to 10-12.5 micrograms/90 min (C; no. = 3). Ovulation rate was 80% in A, 92.3% in B and 100% in C and pregnancy rate 25% in A and 41.6% in B. Furthermore, both the onset of ovarian response and follicular growth were found to be more suitable in groups B and C with respect to group A. Estradiol pattern as well as mid-luteal progesterone plasma levels were superimposable in the different groups. It is concluded that all doses used are effective in inducing ovulation in HA patients. However, small pulsatile doses (2.5 micrograms/90 min) might constitute a critical threshold for adequate ovarian response.