Question
What is ABO blood incompatibility?
Answer
ABO blood incompatibility is an alloimmune hemolytic reaction that can occur between the mother and the fetus within the womb. Particularly, if the mother is an O-negative (RH negative) and the fetus is A-type or B-type (RH positive), there is a possibility for this type of hemolytic reaction to occur. In such cases, the mother may develop antibodies against the fetus’s red blood cells, which can enter the fetus’s body and trigger a hemolytic reaction. Unlike Rh hemolytic disease, ABO hemolytic disease can occur in the first pregnancy. The cause is often that the mother already has immunity to natural A-type or B-type antigens, and these antibodies can enter the fetus’s body, leading to a hemolytic reaction.