Question

Why do mothers that are Rh negative with husbands who are Rh positive must be evaluated and immunized many times during pregnancy?

Answer 1

The most common problem with RH incompatibility may arise during pregnancy .If a small amount of RH+ blood leaks from the fetus through the placenta into the bloodstream of an Rh negative mother,the mother will start to make anti Rh antibodies .Since the greatest possibility of fetal blood transfer occurs at delivery, a newborn baby will be unaffected .If the mother pregnant again ,however her antiRh antibodies can cross the placenta and enter the blood stream of the fetus .If the fetus is Rh positive hemolysis occur in the fetal blood and it is called hemolysis disease of the newborn.

It is one of the major cause for newborn death and it is prevented by giving Rh negative mothers an injection of anti Rh antibodies called anti Rh gamma globlin and it is given during 28week of pregnancy and then within 72 hours after delivery if theRh negativemother delivers Rh postive fetus but remains unsensitized.These antibodies bind to activate the fetal Rh antigens ,if they are present .so the mother'simmune system doesnot respond to the foriegn antigens by producing antibodies.Thus fetus of the next pregnancy is protecteted