Red Blood Cell Alloimmunization in the Pregnant Patient

Alloimmunization to red blood cell (RBC) antigens represents a challenge for physicians caring for women of child bearing potential. Exposure to non-self RBC antigens may occur during transfusion or pregnancy leading to the development of antibodies. If a subsequent fetus bears that antigen, maternal antibodies may attack the fetal red blood cells causing red cell destruction and clinically significant hemolytic disease of the fetus and newborn (HDFN). In the most severe cases, HDFN may result in intrauterine fetal demise due to high output cardiac failure, effusions and ascites, known as “hydrops fetalis”. This article reviews strategies for management and prevention of RBC alloimmunization in women of child bearing potential. •Alloimmunization to red blood cell (RBC) antigens represents a challenge for physicians caring for women of child bearing potential.•Although rare, HDFN may result in intrauterine fetal demise due to high output cardiac failure, effusions and ascites, known as “hydrops fetalis”.•Once a mother is identified as having a clinically significant RBC alloantibody, further monitoring with serial antibody titers and ultrasounds of the middle cerebral artery of the fetus are used to guide the need for in-utero transfusions.•Strategies, such as RhIg and extended matching of transfused blood, have been shown to prevent RBC alloimmunization from occurring.