Leptin supplementation in embryo culture medium increases in vivo implantation rates in mice

Leptin is a hormone-like protein consisting of 167 amino acids. The aim of this study is to compare the effects of different leptin concentrations on in vitro and in vivo embryo development rates. In vitro development rates were investigated by embryo culture studies, and in vivo implantation rates and the quality of embryos were assessed by embryo transfers to the recipient mice. The results showed that addition of leptin into the embryo culture medium at 10 and 100 ng/mL doses supported the in vitro development of mouse embryo. Moreover, leptin increased the total cell number of blastocyst, particularly the trophectoderm cells. In vivo assessment showed a significant increase in the proportion of the embryos implanted in 10 and 100 ng/mL groups, compared to the control group. In conclusion, leptin supplement in embryo culture medium increases implantation rates in mice.