Erythroblastosis fetalis. (a) The condition occurs with an RH+ father and RH– mother. (b) First preg

Erythroblastosis fetalis. (a) The condition occurs with an RH+ father and RH– mother. (b) First pregnancy with an RH+ fetus stimulates the mother’s blood to form antibodies against the fetal blood. (c) As the placenta separates during birth, the mother is further exposed to the RH+ blood, increasing her blood’s reaction against it. (d) The mother carries antibodies against the RH+ blood. (e) In a subsequent pregnancy with an RH+ fetus, the mother’s antibodies attack the RH+ blood of the fetus, causing hemolysis of the fetal red blood cells resulting in the disease that can kill the child.