Patient's question:
I am a pregnant woman with RH negative O-type blood. My husband is O-type positive. I am currently 4 months pregnant. In the past, when I didn't know I was RH negative, I had an induced abortion for a fetus (about 45 days old). I don't know if this baby will develop hemolysis. If it does, what should I do?Doctor's answer:
The causes of maternal-fetal blood type incompatibility are Rh and ABO blood types. Rh incompatibility occurs when the mother is Rh-negative, the husband is Rh-positive, and the fetus is also Rh-positive. This is because the dominant antigen inherited from the father enters the mother's body through pregnancy, miscarriage, or delivery, prompting the mother to produce antibodies against the antigen. When these antibodies cross the placenta into the fetus, they destroy and agglutinate the fetal red blood cells, causing severe hemolysis in newborns. ABO incompatibility occurs when the mother is type O blood, and the husband is type A, B, or AB blood. If the fetus is type A or B blood, ABO incompatibility forms, clinically known as ABO hemolysis. This is because fetal red blood cells entering the mother's blood stimulate the mother to produce corresponding antibodies. When the antibody level in the fetus reaches a certain threshold, the antigen-antibody reaction leads to massive red blood cell destruction, causing hemolytic disease of the newborn. This condition typically occurs within hours after birth, with symptoms such as progressive jaundice, anemia, lethargy, poor feeding, vomiting, convulsions, and spasms, even leading to kernicterus in severe cases, which can result in death within 3-5 days. Surviving infants often suffer from long-term sequelae such as intellectual and motor dysfunction. Severe hemolysis during fetal development can lead to miscarriage, premature birth, or stillbirth. Therefore, during prenatal examinations, it is necessary to test the blood types of both parents. If the pregnant woman is type O blood and the husband is non-O blood, further testing of the mother's serum antibody levels is required. When antibody levels reach a certain concentration, appropriate preventive measures should be taken, including administering large doses of vitamins B, C, and E, folic acid, glucose, and oxygen to protect fetal red blood cells, promote red blood cell regeneration and repair, enhance fetal resistance, reduce maternal antibody levels, and strengthen the placental barrier to prevent immune antibodies from entering the fetus. Clinical observations also suggest that traditional Chinese medicine with blood-activating and blood-stasis-resolving effects can help reduce maternal antibody levels. Intrauterine fetal blood transfusion and timely termination of pregnancy, allowing the fetus to safely exit the dangerous situation, are also effective measures. Women with a history of stillbirth, stillbirth, or neonatal hemolysis must undergo blood antibody titer testing during subsequent pregnancies. If the ABO incompatibility antibody titer reaches 1:512 or the Rh incompatibility antibody titer exceeds 1:32, the condition is severe and requires prompt intervention. Generally, pregnant women with blood type incompatibility should undergo regular monitoring at specialized hospitals to prevent and minimize harm.