Clinical use of growth hormone-releasing factor for induction of superovulation

A consistent body of in vivo and in vitro evidence suggests that insulin-like growth factor-I (IGF-I) and possibly growth hormone (GH) play a stimulatory role in the regulation of the ovarian follicular cycle. Administration of GH in protocols of induction of superovulation gave promising results. In the present study, 10 patients with a previously normal response to gonadotrophins were administered s.c. GH-releasing factor (GRF) combined with gonadotrophins for superovulation induction in an in-vitro fertilization/embryo transfer-gamete intra-Fallopian transfer (IVF/ET-GIFT) programme. Administration of GRF was followed by shortening of the stimulatory cycle and reduction of the total number of gonadotrophin ampoules utilized per patient relative to a previous stimulatory cycle with gonadotrophins alone. A significant increase of both follicular fluid IGF-I levels (compared to the previous cycle) and plasma GH levels immediately following GRF administration throughout the GRF cycle suggest that GRF supported the ovarian response to gonadotrophins through stimulation of the GH-IGF-I axis. A possible direct effect of GRF is discussed. Before employing GRF for superovulation in infertile patients, the pituitary GH response to provocative stimuli should be evaluated on an individual basis.