Blood type check for pregnancy
Haemolytic disease of mother and child is a homozygous immune disease related to blood group, which occurs in the fetal and early neonatal period and is the main cause of haemolytic disease in newborns. Due to maternal and child blood group incompatibility, the red blood cell antigen inherited by the father of the fetus, which is lacking in the mother, can enter the mother’s body through the placenta and stimulate the production of the corresponding immune antibodies. If another pregnancy is still stimulated by the same antigen, the production of the antibodies will increase rapidly, and the antibodies in the serum of the pregnant mother will then enter the blood of the fetal baby through the placenta, causing the fetal baby’s red blood cells to agglomerate and destroy, and fetal-neonatal hemolytic disease will occur. The danger of this disease is that it can lead to recurrent miscarriage, premature birth, stillbirth, neonatal hemolysis or unexplained neonatal death. Therefore, it is important to pay attention to high-risk groups in perinatal care.
ABO blood group incompatibility
ABO blood group incompatibility is the main cause of neonatal hemolytic disease in China, accounting for 96% of the cases, mostly in pregnant mothers with O blood group.
The mother’s blood type O is sensitized by the fetal baby’s type A or B antigen and produces anti-A or anti-B IgG immune antibody, which enters the fetal baby’s blood circulation and binds to the corresponding fetal baby’s red blood cell surface antigen site and hemolysis occurs. China’s statistics ABO blood group incompatibility accounted for 27.7% of the total number of births, with clinical symptoms of 5%.
In addition, only 5% of Rh-negative pregnant mothers have hemolysis; if the fetal baby is Rh-positive, Rh hemolytic disease does not necessarily occur. Only if the mother is Rh-negative and the husband is Rh-positive, there is a risk of neonatal Rh hemolysis during the second pregnancy.
It is important to check the blood type during the maternity checkup
It is important to check the mother’s blood type, including ABO and Rh blood type, during the maternity checkup.
For O-blooded pregnant mothers, it is important to know exactly the ABO blood type of the husband; for Rh-negative pregnant mothers, it is important to know the Rh blood type of the husband.
If the husband is type A (B or AB) and the pregnant mother is type O, there is a possibility of ABO blood group incompatibility between the mother and child.
If the husband is Rh-positive and the mother is Rh-negative, there is a possibility that the mother and child are not of the same Rh blood type.
In addition to knowing the blood type, those at high risk for the presence of ABO or Rh blood group incompatibility should be monitored regularly during pregnancy for these.
ABO hemolytic disease by quantitative anti-A(B) IgG method: If IgG anti-A(B) antibody ≥ 1:128, it suggests that ABO hemolytic disease may occur in the fetal baby or newborn; if the antibody potency is above 1:512 it suggests a serious condition.
Rh antibody measurement: Rh blood group incompatibility anti-D antibody potency of 1:16, indicating fetal baby hemolysis; if the anti-D antibody potency ≥ 1:32, indicating a serious condition.
Ultrasound examination: to understand the growth and development of fetal baby, whether there are signs of edema, the amount of amniotic fluid, changes in blood flow of fetal baby (especially the blood flow value of middle cerebral artery of fetal baby is good predictor for determining the anemia of fetal baby).
Amniotic fluid examination: to know the indicator of bilirubin in the amniotic fluid from the fetal baby.
Umbilical cord blood puncture: to know the blood type (ABO blood type and Rh blood type), hematocrit, antibody titer, etc. of the fetal baby.
The above indicators can determine the possibility and severity of maternal and child blood group incompatibility during the fetal period. Confirmation of the diagnosis also needs to be determined by the corresponding indicators of the newborn (such as blood group, hemoglobin, bilirubin, etc.). In addition, placental edema is one of the supporting evidence for this disorder.
Treatment
During pregnancy, treatment of maternal-fetal blood group incompatibility can be done with herbs, western medicine, and in severe cases, maternal plasma exchange or intrauterine fetal baby blood transfusion. For those who have obvious evidence of blood group incompatibility during fetal life and the condition is serious, the pregnancy needs to be terminated promptly. Newborns are immediately transferred to pediatrics for treatment, including phototherapy, medications, blood exchange, etc.
Prevention
For those at high risk of ABO blood group incompatibility, herbal treatment can be tried if the antibody potency is high during non-pregnancy.
For pregnant mothers with Rh blood group incompatibility, intramuscular injection of anti-D immunoglobulin 300ug is recommended at 28 and 34 weeks of gestation and within 72 hours after delivery; if no maternal and child Rh blood group incompatibility is found during pregnancy but the mother is found to be Rh negative after delivery, it should also be administered as early as possible within 72 hours after delivery. If invasive operations such as amniocentesis or cord blood puncture are required during pregnancy, preoperative intramuscular injection of anti-D immunoglobulin 300ug is also required to protect the fetus in this pregnancy. In addition, care should be taken to use effective contraception, avoid abortion and importation of Rh-positive blood in general.