Question
After a newborn undergoes a blood test in the hospital, the doctor diagnoses a possible hemolytic condition. What are the causes of hemolysis?
Answer
Hemolysis usually occurs due to blood type incompatibility between the mother and child, triggering a blood group immune response in a genetic disorder. When a fetus inherits a dominant antigen from one parent that the mother lacks, this antigen invades the mother’s body, producing immune antibodies. These antibodies then pass through the placental villi into the fetal bloodstream, agglutinate with fetal red blood cells, and destroy them, leading to hemolysis. This can further result in anemia, edema, enlargement of the liver and spleen, and the appearance of progressive severe jaundice within a short period after birth. In some cases, if the fetus inherits a blood type antigen from the father that is different from the mother’s, it may also stimulate the mother to produce corresponding antibodies. These antibodies can then pass through the placenta into the fetus’s body, leading to antigen-antibody reactions with fetal red blood cells and causing hemolysis.