What is Blood Incompatibility?
The Rhesus factor or Rh factor is a type of protein found on the surface of red blood cells. People are either Rh positive or Rh negative. Those who are Rh positive have this protein, while those who are Rh negative do not. The Rh factor, a type of protein found on the surface of red blood cells, is genetically inherited. About 85% of people carry this protein.
During pregnancy, blood incompatibility occurs if an Rh-negative woman is carrying an Rh-positive baby. This can lead to various complications, but treatments are available to prevent these issues. Blood incompatibility can also occur when there is a difference in blood type between the mother and baby. This condition can cause hemolytic disease in newborns.
However, the complications of this incompatibility are less severe. Known as ABO incompatibility, this occurs when the mother's blood type is O and the baby's is A, B, or AB. The mother's blood type O does not recognize A or B antigens, causing the immune system to attack.
Blood Incompatibility Diagnosis Criteria
During the first three months of every pregnancy, a simple blood test evaluates the Rh factor. The results of the Rh factor test determine the Rh compatibility between the mother and baby. If the mother's Rh factor is positive, there is no danger. However, if the mother is Rh negative and the antibody screening is not negative, experts recommend using Rh immune globulin to prevent antibody formation. If doctors think the mother's blood has mixed with the fetus's blood, Rh immune globulin should be used early in pregnancy.
Blood Incompatibility Symptoms
Blood incompatibility symptoms are severe cases diagnosed before the incompatible baby is born. These babies are managed by maternal-fetal monitoring. In less severe cases, symptoms appear after birth. Initially, excessive bilirubin in the baby's blood can cause jaundice immediately after birth. In some cases, the baby develops anemia.
Causes of Blood Incompatibility
Blood incompatibility occurs when an Rh-negative mother becomes pregnant with an Rh-positive baby. Rh incompatibility happens when the immune system reacts to this difference and forms antibodies. These antibodies attack the red blood cells, perceiving the fetus as a foreign object.
During pregnancy, there is no blood sharing between the mother and baby. However, during delivery and labor, a small amount of blood from the fetus may mix with the mother's blood. The following situations can also occur:
- Amniocentesis tests
- Chorionic villus sampling
- Vaginal bleeding during pregnancy
- Abdominal injuries or trauma
- Early pregnancy complications such as miscarriage or ectopic pregnancy
- External cephalic version to turn a breech baby
Blood Incompatibility Treatment Methods
Rh immune globulin is a medication that stops the body from producing Rh antibodies. This medication is only beneficial if the body has not already produced Rh antibodies. It is administered as an injection. Identifying Rh incompatibility early in pregnancy is the most effective way to reduce the risk of severe complications.
If Rh antibodies are present in the body, the fetus is at risk for Rh disease. In this case, Rh immune globulin is not effective, and close monitoring of the pregnancy is the best treatment option. In rare cases, doctors may recommend early delivery. However, if the fetus has severe Rh disease, early delivery may be advised.
Blood Incompatibility Complications
Rh incompatibility does not affect the mother but can cause hemolytic anemia in babies. Hemolytic anemia occurs when the destruction of red blood cells is faster than the fetus can replace them. The effects of Rh incompatibility can range from mild to severe. These effects include:
- Jaundice
- Liver failure
- Heart failure
- Stillbirth
No treatment is necessary for mild effects in babies. Most fetuses with mild Rh disease recover completely. In severe cases, a blood transfusion may be needed to replace red blood cells. Doctors may use phototherapy to lower bilirubin levels in babies with jaundice. Early delivery may be required to avoid serious complications of anemia.
Jaundice due to blood incompatibility appears within the first day after birth and can be very severe, potentially leading to cerebral palsy.
