Incompatibility during pregnancy

If fother's  blood is Rh+ and mother's blood is Rh- the foetus blood is Rh+ . This is a serious problem. If the Rh- blood of mother has not earlier come in contact with Rh+ blood through transfusion, her first child does not suffer (although the Rh+blood of the foetus Stimulates the formation of anti Rh factor sir the antibodies in the mother's blood yet enough anti Rh factors are not produced in the mother's blood to harm the foetus).But in the subsequent Rh+ foetuses,the anti rH factors of the mother's blood destroy the foetal red blood corpuscles.This results in heamolytic disease of the newborn(HDN).It is called erythroblastosis foetalis.Newborn may survive but it is often anaemic.In order to prevent HDN,Rh- mothers are injected with a defective anti Rh antibody during all pregnancies Rh+ foetus.Marriage between Rh- women and Rh+ man is not recommended.Rh+ is dominant