Immunological uterine response to pig embryos before and during implantation

The establishment of a successful pregnancy can only occur through a concerted functioning of the entire female reproductive system, allowing for fertilization, subsequent embryo development and implantation of the conceptus. In this context, the uterine immunological responses responsible for rejection or tolerance of the conceptus are of critical importance. The aim of the present review is to summarize our current knowledge about those cellular and molecular immunological events occurring at the uterine level during pre-implantation and implantation stages of pregnancy in the pig. Advancing our understanding of the immune mechanisms involved in the success or failure of pregnancy will provide cues to develop novel strategies augmenting endometrial receptivity, finally increasing the efficiency of assisted reproductive technologies in pigs.