Patient's question:
Hello! I would like to ask, I am O-type blood with RH positive, and my husband is AB-type blood. I don't know what his RH status is. I am currently 32 weeks pregnant. How can I find out if the fetus will have ABO blood incompatibility?Doctor's answer:
Analysis of the Condition: Neonatal hemolytic disease refers to immune hemolysis caused by incompatibility between the blood types of the mother and the infant. In China, the majority of cases involve ABO blood type incompatibility, while Rh incompatibility is less common. When the blood type antigen inherited from the father differs from that of the mother, entering the maternal body stimulates the mother to produce corresponding antibodies. These antibodies can cross the placenta into the fetus, leading to an antigen-antibody reaction with fetal red blood cells, causing hemolysis. In the ABO system, individuals with type O blood have a higher prevalence of anti-A or anti-B antibodies compared to those with type A or B blood. The A antigen is stronger than the B antigen, so when the mother is type O and the fetus is type A, the risk of disease is higher. ABO hemolytic disease can occur in the first pregnancy, often due to the mother having previously been exposed to antigens similar to A or B substances in nature, resulting in the presence of anti-A or anti-B antibodies. Rh hemolytic disease is caused by immune antibodies that can only be produced when human blood cells serve as antigens. If fetal red blood cells enter the mother's body only during childbirth, except in cases with a history of blood transfusion, it is rare for the disease to develop in the first pregnancy. Since the majority of people in China are Rh-positive, Rh hemolytic disease is uncommon in the country. When a mother is type O and the child is type A or B, resulting in hemolysis, it is called ABO hemolysis. When the mother is Rh-negative and the child is Rh-positive, causing hemolysis, it is called Rh hemolytic disease.Guidance: Pregnant women with type O blood should undergo antibody titer testing. The testing times are: the first time at 16 weeks of pregnancy, the second time at 28-30 weeks of pregnancy, and then every 2-4 weeks thereafter. More than half of these pregnant women will develop antibodies after 28 weeks. When the antibody titer is >1:128, there is a risk of hemolysis. Additionally, ultrasound can also help detect fetal hemolysis. If fetal skin edema, pleural and abdominal effusion, hepatosplenomegaly, or placental enlargement is observed, the possibility of maternal-fetal blood type incompatibility should be considered. However, type O blood mothers should not be too anxious, as not all babies of type O blood mothers will develop hemolysis. Moreover, ABO hemolysis is generally mild, and with careful observation of jaundice appearance after delivery, early diagnosis and treatment can lead to a good prognosis. We advise you to relax and focus on regular prenatal check-ups!