What Is Maternal Alloimmunization?
Maternal alloimmunization occurs when a pregnant person’s immune system forms antibodies against their baby’s red blood cells. This happens when the baby inherits certain proteins (antigens) from the father that the mother’s body identifies as foreign. These antibodies can cross the placenta and attack the baby’s red blood cells, leading to Hemolytic Disease of the Fetus and Newborn (HDFN). HDFN can cause anemia, jaundice, heart failure, stillbirth, and infant death. With the right monitoring and treatment, though, it is often short-term and manageable.