Rh incompatibility poses a very low risk to mother or baby with a first-time pregnancy. The risks of Rh incompatibility increase significantly with subsequent pregnancies, however, especially if the mother is not aware of the condition. Babies affected by Rh incompatibility may suffer mild to severe symptoms ranging from jaundice to hearing loss to retardation, seizures, or death. Rh incompatibility occurs in only a small percentage of pregnant women and happens only when the mother has an Rh-negative blood type and the fetus develops an Rh-positive blood type. The odds of a fetus developing an Rh-positive blood type are 50% when an Rh-negative mother conceives with an Rh-positive partner.
The risk of Rh incompatibility can be assessed with a simple blood test that is administered routinely as part of prenatal care. In a first pregnancy, Rh incompatibility rarely affects the baby, but can affect subsequent pregnancies if the mother’s blood develops antibodies against the Rh-positive proteins. If this happens, then any subsequent conceptions can be affected as the antibodies may work to destroy the red blood cells in any Rh-positive fetus she may carry.
Complications from Rh incompatibility are preventable with proper prenatal care. When a mother is found to be Rh-negative, then the possibility of Rh incompatibility exists. To prevent complications, the mother is given a series of injections called Rh immune-globulin, which function as a vaccine to prevent the mother from developing the antibodies that could harm a future fetus.
If doctors learn that a woman has already developed Rh antibodies, they will closely monitor the pregnancy and can proceed with an exchange transfusion treatment if necessary. An exchange transfusion is a special type of blood transfusion that prevents damage to the developing fetus’s blood cells. Since the development of Rh immune-globulin injections, exchange transfusions are rarely necessary in women who have sought proper prenatal care beginning with their first pregnancy.
Though complications with Rh incompatibility are rare, the development of Rh disease can be dangerous for a developing fetus and newborn, posing a risk for jaundice, anemia, brain damage, and even death. There is no need to take this risk, and it can be avoided by seeing an obstetrician to determine your Rh factor as soon as you think you might be pregnant.
