Rh Negative and Pregnancy

Seventeen percent of Caucasians are Rh negative. What this means is that they lack the so-called Rhesus factor in their blood. (Their blood type can be A, AB, or O negative). If the baby's father is also Rh negative, the baby will be negative and there will be no possibility of incompatibility. If the baby's father is positive, the baby could be negative if he carries a recessive trait, but most likely the baby will be positive. This can be a concern for a pregnant woman.

In the 1960s, Rhogam, a form of a vaccine, was developed that prevents the Rh negative mother from producing antibodies to the Rh antigens in the blood. Even before knowing the baby's blood type, Rhogam will be offered to you after spontaneous bleeding, car accidents, major falls, routinely at 28 weeks, and within 72 hours of the delivery postpartum.

It is important to receive Rhogam if your baby is Rh positive as quickly as possible. If the mother does not take Rhogam and becomes pregnant again, her antibodies may attack the next Rh-positive baby's blood cells and can cause severe anemia and jaundice.