The child's blood type depends on both the mother and the father, so the fetal blood type is not necessarily the same as the pregnant woman's blood type. In most cases, different blood types between mother and fetus will not cause any harm, because the blood circulation of mother and fetus is actually not directly connected, but is separated by the so-called "placental barrier". Therefore, the mother's red blood cells will not enter the fetal blood circulation, and vice versa. The fetus' red blood cells will not enter the mother's blood circulation. But there are occasional exceptions. The fetal red blood cells enter the mother's body through the placenta with small cracks, or under pathological conditions, such as placental damage, cesarean section, artificial abortion, etc. in the previous pregnancy, fetal red blood cells can also enter the mother's body. This All may stimulate the mother to produce an antibody called IgC. This antibody can enter the fetus through the placenta and react chemically with fetal red blood cells, causing red blood cell destruction and hemolysis. In severe cases, it can cause miscarriage, premature delivery, intrauterine fetal death or neonatal death. Hemolysis.

Neonatal hemolytic disease is more harmful to newborns. Children will develop jaundice, anemia, hepatosplenomegaly, and edema within a short period of time after birth. If the nervous system is involved, the body may suffer from tonic spasm and even respiratory failure. die. Even if it survives, it affects intellectual development and neurological function.

There are roughly two types of hemolytic disease caused by blood group incompatibility between mother and child. One is ABO blood type incompatibility. Generally, it is only seen when the mother has blood type O and the fetus has blood type A or B. The disease can occur in the first child, but the disease is often relatively mild and less harmful. The other is RH blood group incompatibility. Han people are generally RH positive, and only 0.34% are RH negative. If the mother is RH negative, the fetus may develop the disease if it is RH positive. It is more common in the second child, and the condition is generally more severe.

For pregnant women who are suspected of having fetal or neonatal hemolytic disease, such as pregnant women who have had a stillbirth, stillbirth or a child with hemolytic disease in the past, both the couple should go to the hospital for blood type testing when they become pregnant again. Serological tests and related antibody tests can be used to predict the possibility of fetal or neonatal hemolytic disease, so that preventive measures can be taken early and rescue plans can be designed. For children who have already suffered from hemolytic disease, exchange transfusion and phototherapy can be effective Reducing central nervous system complications is extremely beneficial.