The relationship of mother and fetus has absorbed immunologists for decades. Survival of the semi allogeneic fetus was utilised immune tests are as an example of immune liberality to the fetus by the maternal immune system [1]. Numerous hypotheses connected to placental conservation of the fetus, including declaration or lack of declaration of histocompatibility antigens on fetal substance, maternal immune patience to fetal antigens, and inhibition or directive of maternal antifetal immune responses have been put forth to describe the survival of the immunogenic fetus.

Part of the struggling in studying these mechanisms is due to the difference among species in which such examinations are conducted. Mice are used for many of these researches because of their short gestational time, relatively at lower cost, well-defined genetics including mutant, transgenic, and knockout strains and inherence of an extensive spectrum of antibodies and reagents to carry out immunologic and molecular studies [2]. However, dissimilarity in the reproductive system in general and the fetomaterno-placental unit in specific, as well as differences in the evolution and function of immune elements, often preclude direct supplement of results observed in mice to humans. In contrast, studies designed to look into such questions in humans are unethical, and studies incorporating nonhuman primates for these examinations raise similar moral issues and are also prohibitively expensive [3].