Rh Factor

Rh Factor

Rh is an aglutinogen of RBC of a monkey called Rhesus. This antigen is called the Rh factor according to the name of the monkey called Rhesus. The presence of Rh factor in human body is called Rh+ (positive) and the absence of Rh factor in the blood is called Rh- (negative).

The Importance of Rh factor: If the Rh- blood is donated to Rh+, there will be no reaction for the first time. But antibody in the plasma of the receipient will continuously produce the opposite antibody of Rh+ antigen. This antibody is called anti Rh factor. If the receipient receives the Rh+ group for the 2nd time then the RBC of donor will be clotted for the effect of anti Rh factor of plasma of receipients. But if the receipient does not receive the blood for the second time then all the anti Rh factor will be damaged gradually and the receipient will get the normal blood. Rh factor is very important for pregnant women. If a Rh negative woman gets married with a Rh+ man, their first child will be Rh+, because Rh+ is the dominant character. In the embryo stage RBC of Rh+ factor of child will reach to the blood through placenta and as the blood of mother is Rh- then her plasma will create anti Rh factor or antibody. The blood of the mother of anti Rh factor reaches to the blood of embryo through placenta and kills the RBC of the embryo. So the embryo is damaged and abortion occurs. Even if the baby survives, it suffers from severe anemia and jaundice. As the opposite antibody is produced very slowly to the mother’s body, no harm is caused to the first child and it remains healthy. But the complexity starts from the next pregnancy and the embryo dies. So, blood test should be done for the bride and bridegroom before marriage. Couple should have the same Rh factor (either Rh+ or Rh-).