Objective: To document the persistence of a sensitizing effect of human growth hormone on the ovarian responsiveness to human menopausal gonadotrophin in anovulatory patients resistant to standard gonadotrophin doses.
Design: We performed an open study of three patients given 4, 12 or 24 IU recombinant growth hormone on alternate days for 5-7 doses, concomitantly with gonadotrophin, and assessed gonadotrophin dose requirements before, during and after the cycle of growth hormone therapy.
Patients: We studied two with isolated gonadotrophin deficiency and primary amenorrhoea and one with a pituitary tumour and hyperprolactinaemia which normalized with bromocriptine but in whom there was persisting secondary amenorrhoea.
Measurements: We measured body mass index, FSH, LH, prolactin, growth hormone, insulin-like growth factor I (IGF-I), oestradiol and inhibin at baseline and growth hormone, IGF-I, oestradiol and inhibin during treatment. In addition we noted the numbers of ampoules (75 IU) and the last pre-hCG dose of gonadotrophin used before, during and after growth hormone therapy.
Results: Baseline growth hormone levels were low but IGF-I levels were normal. IGF-I increased by 20% in the subject given 4 IU growth hormone, and by 50-100% in the other two. Pretreatment daily gonadotrophin dosage of 8-11 ampoules pre-hCG was reduced to 3-6 ampoules during growth hormone and 3-4 post growth hormone. This effect persisted for 4 cycles over 7 months in one subject.
Conclusion: Growth hormone causes persisting ovarian sensitization to gonadotrophin and may produce a substantial lowering of gonadotrophin requirement for ovulation induction in patients with large dosage needs.