Find out what it means to be Rh negative and pregnant
The "Rh factor" in a blood type refers to the so-called Rhesus antigen (a type of protein) on the surface of blood cells. Approximately 15% of all individuals are Rh negative, which means their blood cells do not have the Rh factor. (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 Rh 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 during pregnancy as the mother's body can produce antibodies to combat the Rh antigen.
When this happens the antibodies break down the fetus's red blood cells and produce anemia (the blood has a low number of red blood cells). This condition is called hemolytic disease or hemolytic anemia. It can become severe enough to cause serious illness, brain damage, or even death in the fetus or newborn.
In the 1960s, Rhogam, a form of a vaccine, was developed to prevent 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, before certain prenatal tests, 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.