The Immune Responses at the Fetomaternal Interface

During gestation, the maternal immune system is in direct contact with the fetus, with genetic material not only from the mother but also from the father. To prevent the fetus from being identified as a “foreign body,” the maternal immune system must adapt to this new challenge, inducing changes that maintain the gestation until a successful outcome: the birth of the baby. We describe here the several mechanisms that work together to protect the fetus from immunological recognition and rejection. These alterations are developed to create a tolerogenic niche in which the semiallogeneic fetus can develop. More specifically, this chapter focuses on the cellular and molecular changes related to innate and adaptive immunity that occur at the fetomaternal interface. The understanding of the fetomaternal immune cross talk is helpful in getting insights into the pathogenesis of pregnancy complications as well as poor postnatal health.