Fertilization and early embryology: The effect of testosterone on the maturation and developmental capacity of murine oocytes in vitro

A dose-dependent inhibition of meiotic maturation and embryonicdevelopment was observed in both cumulus-enclosed and cumulus-denudedmurine oocytes following incubation in the presence of 10, 20,40, 60 and 80 µM testosterone for 18 h in vitro. Maturationto metaphase II was enhanced in cumulus-enclosed oocytes followingmaturation in the presence of human pre-ovulatory mural granulosacells. However, maturation of cumulus-denuded oocytes was enhancedonly when oocytes were cultured on a monolayer of human polycysticovarian granulosa cells. The presence of cumulus cells had asignificantly positive effect on both oocyte maturation (P =0.002) and embryonic development (P < 0.001). In addition,the presence of follicular cells during maturation improvedthe number of fertilized oocytes reaching the blastocyst stage.These data indicate that the exposure of immature murine oocytesto testosterone during maturation significantly reduces theirability to mature and undergo normal embryonic development.