What causes Rh sensitization during pregnancy?
Rh sensitization can occur during pregnancy if you are Rh-negative and pregnant with a baby (fetus) who has Rh-positive blood. In most cases, your blood will not mix with your baby’s blood until delivery. It takes a while to make antibodies that can affect the baby, so during your first pregnancy, the baby probably would not be affected. But if you get pregnant again with an Rh-positive baby, the antibodies already in your blood could attack the baby’s red blood cells. This can cause the baby to have anemia, jaundice, or more serious problems. This is called Rh disease. The problems will tend to get worse with each Rh-positive pregnancy you have. During your first pregnancy, your baby could be at risk for Rh disease if you were sensitized before or during pregnancy. This can happen if: • You had a previous miscarriage, abortion, or ectopic pregnancy and you did not receive Rh immune globulin to prevent sensitization. • You had a serious injury to your belly during pregnancy. • You had
