Ovarian response to human menopausal gonadotropin after therapy with the gonadotropin-releasing hormone agonist leuprolide

Effects of leuprolide acetate on follicular fluid hormone composition at oocyte retrieval for in vitro fertilization

The follicular fluid (FF) in 91 follicles from 17 women treated with leuprolide acetate (LA) before stimulation with gonadotropins for in vitro fertilization were analyzed for estradiol (E2), progesterone (P), androstenedione, prolactin, and human chorionic gonadotropin (hCG) and compared with the concentrations in 128 follicles from 31 women treated with gonadotropins alone. The FF E2 concentration in LA-treated patients was significantly lower than in non-LA patients for all oocyte maturational stages. Follicles containing metaphase II oocytes had significantly lower concentrations of P and hCG in LA-treated patients. These differences persisted when analysis was limited to follicles whose oocytes fertilized normally. These data indicate that in the presence of LA, normal oocyte maturation can occur despite lower intrafollicular concentrations of E2 and P.

Complete ovarian unresponsiveness to hMG stimulation after prolonged GnRH analogue administration

GnRH agonists (GnRH-a) have recently been shown to exert an inhibitory effect on human reproductive functions, the mechanism for this effect being attributed solely to the desensitization of the pituitary gonadotropin receptors to GnRH-a. We present two cases where chronic treatment with a GnRH-a caused complete suppression of ovarian activity in vivo. The effect could not be counteracted by large hMG doses and resulted in high FSH plasma concentrations. Normal ovarian activity was restored only after withdrawal of GnRH-a.