AP BIOLOGY

Detailed explanation-1: -Although it is frequently present in the serum of pregnant women, anti-Lea is not generally associated with HDFN for two reasons; anti-Lea is most often IgM and therefore it does not cross the placenta.

Detailed explanation-2: -HDFN may be caused by anti-K, -Fya or other IgG antibodies. After anti-D and anti-c of the Rh system, anti-K is most likely to cause severe HDFN. This is because maternal anti-K appears to modulate/suppress fetal erythropoiesis causing severe and often fatal anaemia.

Detailed explanation-3: -Anti-D can cause severe hemolytic transfusion reactions and HDFN, but the incidence of anti-D has decreased with the prophylactic use of Rh immune globulin.

Detailed explanation-4: -A major cause of HDN is an incompatibility of the Rh blood group between the mother and fetus. Most commonly, hemolytic disease is triggered by the D antigen, although other Rh antigens, such as c, C, E, and e, can also cause problems.