Obstetrics and Gynecology Specialist Op. Dr. Meral Sönmezer gave important information about the subject. If blood incompatibility is not detected during pregnancy, it is an important condition that can endanger the health of the baby. Although there are about 100 different blood groups and subgroups that differ according to their genetic characteristics, there are 2 universally accepted classifications. Classification according to the ABO system and classification according to the Rh factor. The blood group is determined according to the combination of these 2 factors. The most common incompatibility is the one according to the Rh factor.
Incompatibility by Rh Factor
If the mother is Rh (-) Negative and the father is Rh (+) Positive, the baby in the womb will be Rh (+) Positive with a 50-100% probability. This is determined by whether the father is homozygous or heterozygous. After any blood transfer between the mother and the baby, protective cells, which we call antibodies against the baby's Rh (+) blood, are formed in the mother. While there is usually no problem in the first baby, if the baby is positive in the second baby and these cells pass to the baby through the placenta, it will attack the baby's blood cells and cause their destruction. Blood incompatibility can also occur in the first pregnancy, although rarely, in women who have heavy bleeding during pregnancy, that is, women with a miscarriage threat.
How Does a Blood Incompatibility Problem Harm the Baby?
Due to the exchange between the mother and the baby, the transmission of red blood cells from the baby to the mother and the formation of antibodies in the mother is called Rh immunization. These antibodies in the mother pass to the baby through the cord tie in the second pregnancy and break up the red blood cells in the baby's blood. Due to the blood cell destruction that occurs, the baby develops anemia and heart failure. If no intervention is made for Blood Incompatibility, this picture may result in the death of the baby. As a result of extreme anemia and heart failure, hydrops fetalis is detected. The most common cause of immune-hydrops fetalis is Rh incompatibility. It is seen with an edematous state due to fluid accumulation in various tissues of the fetus. Skin edema, ascites, pleural effusion, and pericardial fluid accumulation are seen in the fetus. This situation is mostly accompanied by polyhydramnios (excess water in the baby). When there is blood incompatibility, jaundice can also be seen. Unlike normal jaundice, since red blood cells bind with antibodies, it may be more severe and may result in death.
Measures to be Taken Against Blood Incompatibility
The most important thing to know for the treatment or prevention of blood incompatibility is the blood group of the mother and father.
In case of Rh incompatibility between the mother and father, the indirect Coombs test should be performed and the test should be repeated at regular intervals.
If the baby's blood group is Rh (+) positive, a protective injection must be given within 72 hours of birth to protect the next baby (rh hyper immunoglobulin).
An early contraceptive injection should be given at the 28th week of pregnancy.
The level of antibodies in the blood is checked in the early months of pregnancy, as the mother may be susceptible. If the value is high, the baby should be followed up in the perinatology outpatient clinic.
Immunoglobulin injection should be given in full dose in abortions older than 3 months. Since red blood cells start to form in the fetus after 3-6 weeks in the first trimester, a low dose is sufficient.
If there is inconsistency in medical reasons or optional abortions, protective injection should be done. Vacuum system should be used as a method.