Answer:
B. Rh-factor incompatibility.
Explanation:
Agent Rh is a blood protein that may or may not be present in human blood. In the first case, the person is said to have Rh (Rh positive); in the other, Rh - (Rh negative). When there is Rh blood incompatibility between mother and fetus, ie, when the mother's Rh factor is negative and the fetus's factor is positive. When this happens during pregnancy, the woman produces anti-Rh antibodies to try to destroy the Rh agent of the fetus, considered "intruder".
Once produced, these antibodies remain in the mother's circulation. If she becomes pregnant again with a Rh-positive baby, the antibodies produced in the previous pregnancy destroy the red blood cells of the fetus. To compensate for this loss, more red blood cells are made, immature in the blood and called erythroblasts.
