Rh is an abbreviation for Rhesus. Everyone is born with a certain blood type that is either Rh positive or Rh negative. Rh incompatibility occurs when the mother's blood type is Rh negative and her fetus's blood type is Rh positive. The possible mixing of fetal and maternal blood can stimulate the mother’s immune system to produce anti-Rh antibodies. The anti-Rh antibodies are not produced in significant amounts until after delivery, therefore, a woman’s first infant is not affected. During the following pregnancies, when fetal and maternal circulatory systems are closely intertwined, the mother’s antibodies may cross the placenta. Hemolytic anemia can form when the mother’s antibodies enter the fetal circulatory system. Rh incompatibility is almost completely preventable. Rh-negative mothers should be followed closely by their obstetricians during pregnancy. If the father of the infant is Rh-positive, the mother is given a mid-term injection of RhoGAM and a second injection within a few days of delivery. These injections prevent the development of antibodies against Rh-positive blood. This effectively prevents the condition. Introduction
Rh incompatibility occurs when the mother's blood type is Rh negative and her fetus's blood type is Rh positive. Rh is an abbreviation for Rhesus. Everyone is born with a certain blood type that is either Rh positive or Rh negative. Rh-positive blood is more common than Rh-negative blood. If the mother is Rh positive, or if both parents are Rh negative, there is no reason to worry about Rh incompatibility. However, if the mother is Rh negative and the baby's father is Rh positive, then the baby may inherit the father's blood type, creating incompatibility between the mother and the fetus. Description of Condition
The Rhesus factor (Rh factor) is a red blood cell surface antigen that was named after the monkey’s in which it was first discovered. Rh incompatibility is a condition that occurs when a woman with Rh-negative blood type is exposed to Rh-positive blood cells, leading to the development of Rh antibodies. The most common cause of Rh incompatibility is exposure from an Rh-negative mother by Rh-positive fetal blood during pregnancy or delivery. As a consequence, blood from the fetal circulation may leak into the maternal circulation and, after a significant exposure, sensitization occurs leading to maternal antibody production against the foreign Rh antigen. Once produced, maternal Rh immunoglobulin antibodies may cross freely from the placenta into the fetal circulation. It is in the fetal circulation where they form antigen-antibody complexes with Rh-positive fetal erythrocytes which eventually are destroyed, resulting in a fetal alloimmune-induced hemolytic anemia. Pathophysiology
Antigens are substances that can trigger an immune response. Cell membranes contain surface antigens that a person’s immune system recognizes as normal. Blood type is a classification determined by the presence or absence of specific surface antigens in red blood cell membranes. The surface antigens involved are integral membrane glycoproteins or glycolipids whose characteristics are genetically determined (Martini, 2006). The term Rh-positive indicates the presence of the Rh surface antigen. The absence of this antigen is indicated as Rh-negative. The Rh system consists of at least eight different kinds of Rh antigens, each referred to as an Rh factor. The most important of these factors is antigen D. About 85% of United States residents who are of western European descent are Rh-positive (Berg, Martin, & Soloman, 1999). This means that they have the antigen D on the surfaces of their red blood cells. Those of the population who are Rh-negative have no antigen D. Rh-negative persons do not naturally produce antibodies against antigen D (anti-D). These Rh-negative people will produce anti-D antibodies if they are...