Embryo implantation: Shedding light on the roles of ovarian hormones, cytokines and growth factors in the implantation process

Abstract

Implantation is a crucial step in mammalian reproduction, as it is a gateway to further embryonic  development and successful pregnancy. Successful implantation requires coordinated interactions between the blastocyst and uterus. Uterine receptivity for embryo implantation is regulated by the ovarian hormones estrogen and progesterone. Some cytokines and growth factors play important roles in embryo implantation under the influence of ovarian hormones. Such molecules are involved in embryo-maternal interactions during the implantation process. This review describes the implantation process and highlights the potential roles of some cytokines and growth factors (such as leukemia inhibitory factor, interleukin-1, interleukin-6, interleukin-11, colony stimulating factor-1, epidermal growth factor family and insulin-like growth factor system) in the implantation process. Knowledge of the function of these molecules during implantation may help to address the reason of implantation failure and infertility.

Key words: Implantation, estrogen, progesterone, cytokines, growth factors.