How Your Mother Tolerated You for Nine Months

Madonna A. de Lemos | Pages 27-30 | BioTeach Online Journal | Vol. 1 | Fall 2003

Mammalian mothers are faced with a problem. The genome of the fetus they carry within their wombs is half maternal and half paternal. Thus, antigens presented by the fetus that are paternal in origin would be considered foreign by the mother's immune system. Logic would dictate that the fetus would trigger an immune response and therefore would be eliminated. However, the presence of billions of humans on the Earth and the continued growth of the human population contradicts this prediction. How does the fetus evade the maternal immune system and survive for nine months in an environment that considers it foreign?