HDN - 3
Mechanisms of Disease cont=d:
ein the case of ABO HDN:
the 1st child may be affected since mom already has the antibodies in her circulatory system
i.e. mom is O type and baby is A or B type
ein the case of Rh HDN:
usually the 1st child is not affected since it is the Rh+ red cells of the fetus that get into moms circulation during delivery and sensitize the mom.