Enhancement of the developmental potential of mouse oocytes matured in vitro by gonadotropins and ethylenediaminetetraacetic acid (EDTA).

We attempted to improve the developmental potential of mouse oocytes matured in vitro. First, the effect of gonadotropin supplementation of the oocyte maturation medium was tested. The addition of follicle-stimulating hormone (FSH) or luteinizing hormone (LH) alone significantly increased the rate of development of inseminated oocytes to two-cell embryos, resulting in a twofold increase in blastocyst development. There was no significant difference between FSH and LH supplementation. However, the beneficial effect of FSH or LH was abolished when both were added together. Next, we tested the effect of ethylenediaminetetraacetic acid (EDTA) supplementation of the embryo culture medium. The addition of 10 microM EDTA significantly enhanced the development of embryos derived from oocytes matured in vitro, both to two-cell embryos and to blastocysts. These data suggest that the inadequate development of embryos from oocytes matured in vitro results from a defect similar to that inherent in outbred mouse embryos showing the two-cell block in vitro.