How should ABO hemolytic disease be checked before pregnancy?

In order to avoid the baby from being born with ABO hemolytic disease, if the woman has type O blood and the man does not have type O blood, then it is necessary to conduct an ABO hemolytic disease test. This test needs to be done during the pregnancy preparation stage and also after pregnancy.

1. When to do ABO hemolysis test

The first best time: before pregnancy. If you know the possibility of ABO blood type incompatibility before preparing for pregnancy, the expectant mother should do a "prenatal blood type serological test" before pregnancy to check the antibodies in the blood. If the "activity" of the antibodies is not high, prospective parents can have peace of mind when giving birth. If the "activity" of the antibodies is very high, it can be reduced through some drug treatments. Now many hospitals have corresponding Chinese medicine treatments. The purpose of doing this is mainly to reduce the "lethality" of the mother's antibodies.

The second best time: 6-7 months of pregnancy. Most couples only learn about neonatal hemolytic disease after they become pregnant. The first test after pregnancy is usually between the 24th and 28th weeks of pregnancy, which can be used as the basic level of antibodies. Thereafter, measure once a month, measure once every half month during the 7th to 8th month of pregnancy, and measure once a week after the 8th month. If the expectant mother's blood type is O type, but the expectant father's blood type is not O type, then the baby may have hemolytic disease of the newborn. Therefore, it is important to do a good job of pregnancy check-up so that early treatment can be given later.

2. Who needs to do ABO hemolysis test

Generally speaking, not every pregnant woman needs to undergo an ABO hemolytic test. According to the characteristics of ABO hemolytic disease, mothers with type O blood must undergo this examination. If the mother has type O blood, the baby's father should be checked if he is not type O blood. If the baby's father has type A blood, the anti-A effect should be checked. If it is type B, the anti-B effect should be checked. If it is AB, both anti-A and anti-B should be checked to prevent hemolysis due to incompatibility of blood types between the fetus and the mother.

3. What does ABO hemolysis include?

1. Blood type antibody test: Pregnant women who suspect that their fetus may have hemolytic disease should undergo anti-blood type antibody testing. The first measurement is usually performed in the fourth month of pregnancy, which serves as the basal level of antibodies. Thereafter, measure once a month, measure once every half month during the 7th to 8th month of pregnancy, and measure once a week after the 8th month. If the antibody titer rises, fluctuates, or changes from high to low, it indicates that the child may be affected. When the antibody titer reaches 1:32, amniotic fluid examination should be performed. Since there are substances similar to A and B antigens in nature, natural anti-A or anti-B antibodies may exist in the mother's body. An antibody titer of 1:64 in ABO hemolytic disease is usually considered a suspected case. The mother's antibody titer remained unchanged, indicating stable disease.

2. Blood type determination: Any mother with a history of unexplained miscarriage, premature birth, stillbirth, or severe neonatal jaundice should be alert to the possibility of maternal and fetal blood type incompatibility. Determine the blood types of the mother and father. If the parents' blood types are incompatible, the mother's blood type antibodies should be measured.

3. Amniotic fluid test: Normal amniotic fluid is colorless and transparent, while the amniotic fluid of severe hemolytic disease is yellow-green. The more severe the degree of fetal hemolysis, the higher the amniotic fluid bilirubin content, so the amniotic fluid bilirubin content can be used to estimate the condition and decide to terminate the pregnancy. The optical density of amniotic fluid at a wavelength of 450nm is in a certain correlation with the bilirubin content in the amniotic fluid. The optical density of amniotic fluid at a wavelength of 450nm can be measured by a spectrophotometer to represent the level of bilirubin in the amniotic fluid. Since the bilirubin content in amniotic fluid decreases with increasing gestational age, the increase in optical density measured at different gestational ages has different meanings.

4. Medical imaging examination: In fetal X-rays of patients with systemic edema, widened zona pellucida in soft tissues and poor flexion of the limbs can be seen. Ultrasound examination showed that the fetus had hepatosplenomegaly and pleural and abdominal effusion.