Rh intolerance

Synonyms

Blood group intolerance

English: rhesus "factor" incompatibility

introduction

The Rh intolerance ( Rh incompatibility, Rh incompatibility) is an incompatibility between maternal and child blood. A Rhesus-negative mother who gives birth to a Rhesus-positive child is typical for the occurrence of an intolerance reaction. This incompatibility can lead to hemolysis of the child's erythrocytes and, in the worst case, to the development of neonatorial disease.

Epidemiology

Before introducing a Anti-D prophylaxis at Rhesus negative Mothers, about 0.5% of all newborns developed Rhesus intolerance. Since the introduction of prophylaxis, the disease has become significantly less common.

causes

Infant blood does not normally spill onto the mother's blood during pregnancy. The first child is usually born healthy. Under the birth mixed however that Blood from mother and child. If the mother is rhesus negative and the child is rhesus positive, it comes to antibodyMaternal formation and it follows the Rh intolerance . These antibodies can die placenta happen and are thus able to pass on to the child when a new pregnancy occurs. This leads to the binding of the antibodies to the fetal Erythrocytes and leads to the destruction of blood cells. This can lead to symptoms and clinical pictures of varying degrees Rh intolerance come.

Such a course can also occur with an abortion, a Termination of pregnancy or an amniocentesis, since maternal and child blood can also be mixed here. Correspondingly, the first child born alive can also be damaged.

Symptoms

Depending on the degree of severity, three different forms of Rhesus intolerance can be distinguished, some of which merge into one another.

1. Anaemia neonatorum: With this form of rhesus intolerance, the children often stand out due to their extreme paleness. However, this can also be a symptom of other diseases and is therefore not directly indicative of a rhesus intolerance. In addition, the extreme blood formation to compensate for the anemia leads to a significantly enlarged liver and spleen (Hepatosplenomegaly)
2. Icterus praecox and gravis: This leads to significantly increased bilirubin levels, which lead to a yellow coloration of the baby. The cause is the destruction of the numerous erythrocytes that are destroyed by the maternal antibodies. When they are broken down, bilirubin is produced that can no longer be broken down in the child's organism. In the worst case, kernicterus can develop. Here the bilirubin crosses the blood-brain barrier and can irreversibly damage the child's brain. The children can die of such jaundice or suffer lifelong severe neurological damage.
3. Hydrops congenitus universalis: This is the most severe form of rhesus intolerance. This leads to massive edema accumulation in the entire child's organism. The cause is severe anemia caused by insufficient oxygen supply (Hypoxia) and acidosis damages tissue. In addition, there is a loss of protein and an increased permeability of the tissue. This leads to edema formation in the body cavities.

also read: Kernicterus

Diagnosis

The diagnosis of rhesus intolerance should start with the prenatal care. Rh-negative mothers must be monitored more closely. An indirect Coombs test should also be performed. This detects the corresponding placenta-crossing antibodies in the maternal serum. In order to be able to accurately assess the child's condition, amniotic fluid has to be taken repeatedly to check the bilirubin level. However, whether the fetus suffers from anemia or how far it has progressed can only be determined on the basis of a fetal blood analysis. This requires an umbilical cord puncture under ultrasound guidance. In addition, edema, enlarged liver and spleen, and pleural effusions can be detected on ultrasound. All of these would indicate that the disease is progressing. The controls must be accordingly tight. This also applies after the birth. Since the bilirubin concentrations can increase rapidly after birth, it is important to check them at short intervals.

For more information, read on: Coomb's test.

therapy

The treatment of rhesus intolerance depends on the course of the disease. The main goal of treatment is to avoid kernicterus and treat anemia.

If the child is at risk of vital health before the 20th week of pregnancy, the only option is a blood transfusion via the umbilical cord or the peritoneum (peritoneum).

Excessive bilirubin levels after birth can be treated most effectively with the help of phototherapy. Phenobarbital can be given as a support. This supports the enzyme activity of the liver. If there is a very rapid rise in bilirubin (Jaundice praecox), an exchange transfusion should take place to avoid kernicterus.

The hydrops fetalis is always an acute emergency for paediatricians and requires intensive medical treatment. The children are usually intubated directly in the delivery room, as they cannot breathe due to the effusions in the lungs. In order to relieve the body cavities, the effusions are punctured and an exchange transfusion is always carried out.

prophylaxis

Within 24 to 72 hours after the birth of the first child, the mother receives anti-D antibodies. This eliminates the fetal red blood cells and prevents sensitization in over 90%. With that the danger is one Rh intolerance for another pregnancy much lower.

Summary

The Rh intolerance can have very serious consequences and therefore requires very close monitoring during and after pregnancy. In most cases, invasive therapy is not necessary to cure the child. It will be between a mostly simple one anemia, hyperbilirubinemia and hydrops congenitus fetalis. Whereby this is life-threatening and intensive medical measures to save the child are inevitable. For this reason, children at risk should be born in the immediate vicinity of a perinatal center in order to be able to help directly with serious problems. In order to avoid rhesus intolerance, the affected mothers are nowadays injected with antibodies shortly after the birth of their first child, which in most cases avoid rhesus intolerance in a second pregnancy.