Page 742 - Veterinary Immunology, 10th Edition
P. 742
VetBooks.ir Transfer of Immunity From Mother to
Offspring
The route by which maternal antibodies reach the fetus is
determined by the structure of the placenta. In humans and other
primates, the placenta is hemochorial; that is, the maternal blood is
in direct contact with the trophoblast (Fig. 23.4). This type of
placenta allows maternal IgG but not IgM, IgA, or IgE to transfer
directly to the fetus. Maternal IgG can enter the fetal bloodstream,
and the newborn human infant has circulating IgG levels
comparable to those of its mother.
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