In Erythroblastosis fetalis, the first child is spared because:
Sensitization of Rh-negative mothers by a Rh-positive fetus generally occurs at bih
Immune response in second exposure is fast
Sensitization of Rh-negative mothers by a Rh-positive fetus generally occurs at bih
Small amounts of fetal blood leak into the ma ternal circulation at the time of delivery
Mothers develop significant titers of anti-Rh ag glutinins during the postpaum period