Effects of a gonadotropin releasing hormone agonist on oocyte maturation, fertilization, and embryonal development of mice.

PURPOSE: The effects of a GnRH agonist (GnRHa) on oocyte quality were investigated by assessing the influence of GnRHa on oocytes, and fertilized oocytes were examined in vivo and in vitro. Administration of gonadotropin in conjunction with GnRHa induced a significantly greater degree of germinal vesicle breakdown, significantly higher rates of in vitro fertilization, and significantly faster development of the oocytes than the pregnant mare serum gonadotropin alone
RESULTS: The hatching-success rate in the GnRHa treated hypophysectomized mice was higher than in control mice. The rate of in vitro fertilization was also higher in oocytes cultured in the presence of low loses of GnRHa and these effects were reversed by a GnRH antagonist.
CONCLUSION: Oocytes obtained following ovarian stimulation with GnRHa were of higher quality than control oocytes, and the efficacy of GnRHa may be due in part to its direct action on the ovary.