Question
My husband has type O blood with positive RH(D) factor, and I am pregnant with a baby of 18 weeks. The blood test shows IgG anti-B antibody titer of 32 and antibody screening is negative. Is there a problem? I’m concerned about how to assist: is it possible to get neonatal hemolytic disease?…
Answer
Neonatal hemolytic disease is an autoimmune condition related to hemolysis that recurs in fetuses and early neonates, primarily seen in the ABO blood group system. The serum IgG antibody titer in pregnant women is significant for the recurrence of hemolytic disease of the newborn (HDN), serving as an important basis for early confirmation and expansion of the criteria. There have been reports that the level of IgG antibody titer in pregnant women’s serum is directly related to the incidence of neonatal hemolytic disease. In clinical diagnosis, a titer of 64 is usually considered as the threshold. If the mother’s serum IgG anti-A (anti-B) titer is ≥64, it indicates a risk for the fetus to be affected, and close observation is required; if the mother’s serum IgG anti-A (anti-B) titer is ≥128, it suggests a high likelihood of the fetus being affected. Clinical diagnosis should emphasize prenatal blood type incompatibility between couples, particularly for pregnant women with blood type O. Therefore, for couples with ABO blood type incompatibility around early pregnancy week 20, it is best to perform routine antibody tests at approximately 16 weeks, 28 weeks, and 36 weeks of pregnancy. For pregnant women with IgG anti-A (anti-B) titer ≥128, necessary rescue measures should be taken to reduce the level of IgG serum antibodies in pregnant women, such as taking oral Chinese medicine Yin Chen Decoction, intravenous injection of vitamin C and 50% glucose, intravenous injection of immunoglobulin, and if necessary, performing plasma exchange or intrauterine transfusion.