ABOG Oral Boards Obstetrics Practice Test

The most common cause of maternal alloimmunization historically has been the presence of anti-Rh (D) antibodies. This occurs when an Rh-negative mother is exposed to Rh-positive fetal blood, often during pregnancy or delivery. If the mother becomes sensitized, her immune system may produce antibodies against the Rh factor, leading to hemolytic disease of the newborn in subsequent pregnancies with Rh-positive infants. This condition is particularly significant because it can lead to severe fetal anemia, jaundice, and even intrauterine fetal demise if not properly managed.

The prevalence of Rh incompatibility issues has led to the widespread use of Rh immunoglobulin (RhoGAM) in Rh-negative mothers, which has drastically reduced the incidence of this complication. While other alloantibodies, such as anti-Kell and various Kidd antibodies, do occur and can lead to similar issues, they are much less common than anti-Rh (D) antibodies in the context of maternal-fetal blood group incompatibility.