Q: What is RH disease?
A: Rh disease is a possibility only when a mothers blood is Rh-negative, the father is Rh-positive and their baby is Rh-positive. Under those circumstances, if a pregnant woman's circulating blood is exposed to fetal blood cells such as during a medical procedure, an abdominal trauma or, most likely, during delivery her immune system may respond by producing antibodies to destroy the Rh-positive cells. Without treatment, this could put a developing baby at risk for serious anemia and other complications.
To prevent this disease, all Rh-negative mothers are given an injection of anti-D immunoglobulin (also called Rhogam) after medical procedures such as amniocentesis and as a prophylactic measure at 28 weeks gestation; mothers of Rh-positive babies also are given an injection within 72 hours of childbirth. This helps confer protection for future pregnancies by keeping a woman's body from storing an immune memory of her baby's Rh-positive cells.