Objective: We have investigated the beneficial effect of a somatotroph axis stimulation on ovarian response to gonadotropin.
Design: Growth hormone-releasing hormone (GH-RH) was administered in a prospective study in women undergoing an in vitro fertilization protocol.
Patients: Twelve patients were selected for their poor ovarian response to previous stimulations using gonadotropin-releasing hormone analog (GnRH-a) and human menopausal gonadotropins (hMG).
Interventions: Five hundred micrograms of GH-RH1-29 were administered two times daily concomitantly with GnRH-a and hMG from day 2 of the cycle to the time of ovulation.
Main outcome measures: Stimulation of somatotroph axis was appreciated by measuring over-night urinary growth hormone (GH) output, plasma GH, and insulin-like growth factor I (IGF-I) and follicular fluid (FF) IGF-I. The effects of GH-RH administration on ovarian function were determined by plasma estradiol levels and follicular data.
Results: Administration of GH-RH was associated with a significant improvement of urinary (P less than 0.025) and plasma (P less than 0.001) GH concentrations and of the hormonal response to hMG (P less than 0.01). Levels of IGF-I followed a biphasic plasma variation, and a slight increase in recruited follicles, retrieved oocytes, and FF IGF-I content was also observed.
Conclusions: Activation of the somatotroph axis by GH-RH enhances the hormonal ovarian response to hMG and may be an adjunctive therapy to improve follicular maturation.