Women with 0 negative blood have a rare blood group. A negative mother and positive father can safely have children together. The problem comes after the second Pregnancy. The mother has no antigens for A, B, or AB blood groups and will treat the antigens from the AB+ father as a foreign particle that has invaded the body and will produce antibodies to destroy this foreign object. Similarly, the positive fetus is treated in a similar fashion and can be destroyed by the mother's body by producing antibodies. An indirect Combs test can be done to indicate the level of antibodies in the mothers' blood. An injection can be taken to reduce the number of antibodies produce and to protect future pregnancies, but it must be administered immediately after the birth of the first child. This injection given after every positive pregnancy will prevent the unborn or soon to be born child from developing a hemolytic disease or if unchecked a blood transfusion at birth.
