Fetus as an allograft: A review

Allograft is a tissue or organ obtained from one member of a species and grafted to a genetically dissimilar member of the same species. Pregnant mother nourishing within itself a fetus acts as an antigenically foreign body. The foreign nature of conceptus, caused by inheritance of genes from its father that encode for proteins foreign to its mother, poses a unique problem for species that are viviparous in which mothers immune system can potentially destroy the conceptus. It requires modulation of the maternal immune system which limits fetal allograft rejection without compromising the ability of the mother to fend off infection. While as tissue (other than fetus) grafted inside uterus is instantaneously rejected by mother/dam. Host T cells responds to peptide epitopes of MHC molecules of grafted cells.