... How common is the Rh-negative factor? Rh disease (also known as rhesus isoimmunization, Rh (D) disease) is a type of hemolytic disease of the fetus and newborn (HDFN). Rh sensitization normally isn’t a problem with a first pregnancy. Rh-negative blood types are more common in people of Northern European heritage and especially those of the Basque region of Spain and France. Image 1 to 4 Shows pathogenesis of rh incompatibility. Your baby could have jaundice, heart failure, and enlarged organs. During that pregnancy, your antibodies cross the placenta to fight the Rh positive cells in your baby's body. Rh sensitization occurs when women whose red blood cells are Rh(D)-antigen negative develop anti-Rh(D) antibodies either during a pre- vious pregnancy in which the fetus is Rh(D)-positive or by exposure to Rh antigens from blood products/transfusion. Rh immunoglobulin (RhIg), a blood product can be injected which prevents sensitization of a Rh-negative mother. Isoimmunization (Sometimes called Rh sensitization, hemolytic disease of the fetus, Rh incompatibility) What is isoimmunization? Rh sensitization can occur. Image 1. If both parents have Rh-negative blood, the baby will have Rh-negative blood. Preventing Sensitization to Rh Factor . If both mom and baby are Rh negative, there won’t be any incompatibility. The process of making antibodies is known as developing Rh sensitization. Most issues occur in future pregnancies with another Rh positive baby. Sensitization to Rh factor can be thought of as developing a reaction to your baby's blood. A condition that happens when a pregnant woman's blood protein is incompatible with the baby's, causing her immune system to react and destroy the baby's blood cells. HDFN due to anti-D antibodies is the proper and currently used name for this disease as the Rh blood group system actually has more than 50 antigens and not only D-antigen. Rh sensitization during pregnancy can only happen if a woman has Rh-negative blood and only if her baby has Rh-positive blood. Image 2. What causes isoimmunization? And mothers who are Rh positive also won’t experience problems, even if their baby is Rh negative. If you are Rh-negative and you are exposed to Rh-positive blood, you can produce antibodies to Rh(D). The body will create antibodies made up of proteins to go against the baby’s Rh-positive blood, where a sensitization then happens. If the mother is Rh-negative and the father is Rh-positive, there is a good chance the baby will have Rh-positive blood. As the antibodies destroy the cells, your baby gets sick. When is RhIg used? More than 85% of people are Rh positive. Image 3. The Rh factor does not affect a person’s general health.