Women with RH-negative anemia are at risk of infant hemolysis if they have three children, so having three children is not recommended.
RH-negative women whose spouses share the same RH-negative blood group will have an RH-negative fetus regardless of the number of births, and can give birth without worrying about the risk of hemolysis in the fetus if the blood groups do not match. However, pregnant women may suffer from hemorrhage during delivery and need to have a sufficient amount of RH-negative blood before the operation.
RH-negative women with RH-positive spouses can deliver their first-born fetus normally. However, if the fetus of the first pregnancy is RH-positive, a small amount of fetal blood can enter the mother’s circulation during delivery in various ways, including bleeding during pregnancy, causing the mother to develop antibodies.
During the second/third trimester, if the child is RH-positive, the mother’s antibodies can cross the placenta and attack the fetal red blood cells, causing hemolytic disease in the baby. The risk of hemolysis increases with the number of pregnancies.
Women with RH-negative anemia are advised to consult a specialist if they need to have a pregnancy.