In vitro treatment of embryos with epidermal growth factor improves viability and increases the implantation rate of blastocysts transferred to recipient mice.

Abstract

Our purpose was to study, by means of a mouse embryo donation model, the possible role of epidermal growth factor in the development of preimplantation embryos. Seven blastocysts developed either in vivo or in vitro, with or without treatment with epidermal growth factor, were transferred to a uterine horn of pseudopregnant recipient mice on day 3 (the presence of a vaginal plug indicated day 1 of pseudopregnancy). Recipients were killed on day 8 of pseudopregnancy, and the number of implantation sites was counted. The implantation rate in recipient mice of in vitro-cultured blastocysts was significantly lower than that of embryos grown in vivo (i.e., 57.1% vs 84.2%) (p < 0.001). Treatment of embryos in vitro with epidermal growth factor, 10 ng/ml, effectively prevented a decrease in implantation rate (77.9%). Epidermal growth factor may play a stimulatory role in the development of the preimplantation mouse embryo.