Originally Posted by patelMD
Goljan RR Patho:
"Blood group O (Universal Donors) individuals are considered universal donors, Anti-A-Igm and anti-B-IgM cannot hemolyze O RBC's"
"ABO HDNB: Mother group O, fetus group A or B"
Now I dont get it, if the mother has group O (universal donor), why would it cause hemolysis in the fetus if type O blood is considered Universal Donor?
I thought it had to do with serum vs RBCs. If the Mom is type O, her RBCs has no antigens. Therefore you can give her RBCs to anyone and their antibodies won't attack the Mom's O cells because they have nothing to bind to. (I like to think of the RBCs as looking like a blank O with nothing sticking out of it so the little Y shaped antibodies have nothing to bind to). However, the Mom's serum have both Anti-A-IgM and Anti-B-IgM, they will cause lysis if donated to another patient with any combination of A or B blood type. They don't lyse the babies RBC's because IgM doesn't cross the placenta. If however the Mom has IgG antibodies in her serum, they can cross the placenta and cause hemolysis.