Hemolytic disease of the newborn

Under the hemolytic disease of the newborn (also: Fetopathia serologica, fetal erythroblastosis fetalis erythroblastosis or ) refers to a serious and complex health disorder of the fetus and the newborn, which occurs before birth, and is called at this time fetalis hemolytic disease. There is usually the cause in a blood group incompatibility in the Rhesus system, but also other states in which there is an injury and resolution of the child's red blood cells (hemolysis ), can be responsible for it. The unborn child develops in the womb a significant anemia (anemia) and, consequently, an oxygen deficiency of the whole organism with Heart failure ( congestive heart failure ), effusions in the chest and abdominal cavity ( pleural effusion and ascites ) and water retention in the whole body (generalized edema). The full image of this state is called the medical hydrops fetalis. Early detection can be attempted, the disease is already through a blood transfusion ( transfusion) to treat in the womb. After birth, the newborn will need at least a phototherapy, if not an exchange transfusion. For the most common cause, the Rh incompatibility, there are in Germany and Austria, a systematic prevention by administration of antibodies against the Rhesus blood group feature to all Rhesus negative mothers immediately after childbirth.

Cause ( pathogenesis )

The prerequisite is that the mother ever contact with a foreign blood type feature for them - usually it is the rhesus feature ( Rh incompatibility ) - had. This can be, for example, in a previous pregnancy happen (even with miscarriage ) or a previously performed blood transfusion. This awareness leads to the production of antibodies of the IgG class against the blood group of the child, which entail crossing over the placenta ( placenta) an enhanced degradation of the loaded erythrocytes with antibodies in the spleen of the child after himself. The fetus tries to compensate for the loss by increasing blood production. Is the breakdown faster than the recharge, the child gets an anemia, leading to a shortage of oxygen (hypoxia ) and thus leads to general tissue damage.

Frequency

The blood group incompatibility is - next to Rhesus incompatibility - with a significantly lower frequency in other blood group characteristics before, so is sought with the antibody screening in pregnancies after a variety of sensitization. The order of the MHN -causing blood group antibodies depends on various factors, since ( with the exception of AB0 ) only leads to a sensitizing antibodies and according to the genotype frequency of the population there is an incompatible blood group in the child. Add to that an incompatibility as in AB- antibodies leads to a mild course that almost never requires treatment. At 98 % of the MHN- diseased Newborn anti-D antibodies were the cause. Anti-C, anti- Duffy and anti - Kidd followed by Kell incompatibility with 9.8%, and - in the residual group first followed by two other rhesus incompatibility - Anti -c in 66%, anti -E with 14.6% each with 2.7 % (both in the residual group of 2 % of all cases). It should be noted that most of the antibody screening tests are negative - clinically significant antibodies are detected only at 0.24 % of the pregnant women.

Symptoms

In the womb first fall an increased water retention in the tissues and eventually bruising in the abdominal cavity ( ascites) and pleural cavity ( pleural effusion) on. The amniotic fluid is also significantly increased ( polyhydramnios ). The Heart failure - causally responsible for most symptoms - can be detected in the womb ultrasound. The full image of these symptoms is called hydrops fetalis also. After delivery, in addition to the anemia and edema, especially premature and very strong neonatal jaundice ( icterus praecox ) on.

Diagnostics

As part of prenatal care, a blood typing and antibody screening test for irregular blood group antibodies is done in early pregnancy. If negative, the latter is repeated in the 24th to 27th week of pregnancy. Regular ultrasound examinations is the development of a fetal hydrops is monitored to possibly also intrauterine too can begin treatment. Both blood can be taken to determine the anemia and blood transfusion are made via the umbilical cord. After the birth ( postpartum ) is performed in addition to the determination of the blood picture a so-called Coombs test, can be detected with the antibody on the red cells. As more blood tests, a determination of bilirubin and hemolysis of various dehydrogenase (LDH, reticulocytes ) are meaningful.

Therapy

If a fetalis hemolytic disease during pregnancy on, it is in principle possible to perform in the womb ( in utero ) through the umbilical cord blood transfusion in order to avoid the development of hydrops fetalis. Postpartum no therapy is in light jaundice which is present in approximately half of the newborn with a Rh incompatibility, it is necessary or sufficient phototherapy. For the other half with severe jaundice, a blood exchange transfusion is accordingly necessary. Administration of immunoglobulins can potentially mitigate the hemolysis. The frame of hydrops fetalis is for neonatologists always an emergency that already in the delivery room attracts a variety of intensive care measures by themselves. In general, the children must be immediately intubated and artificially ventilated immediately receive blood transfusions and the effusions in the chest and abdominal cavities are punctured to relieve.

Prophylaxis

In addition to the regular antibody screening tests in pregnancy for the early detection of hemolytic disease get rh- negative pregnant women in the 28th week of pregnancy and injected antibodies against the Rhesus feature ( anti-D immunoglobulin ) no later than 72 hours after the birth of an Rh - positive baby. This is just after miscarriage ( abortion), amniocentesis ( amniocentesis ), chorionic villus sampling or bleeding required of the placenta. The antibodies loaded the data transferred from fetus erythrocytes and thus lead to a rapid reduction in the spleen of the mother before their immune system can recognize the rhesus antigen and produce its own antibodies. Thus, sensitization is avoided.

History

The haemolytic disease of the newborn was first described in 1609 by a French nurse in twins: one neonate was born with hydrops fetalis dead and the second had a severe jaundice and died of what we call today kernicterus. These two states were in 1932 again brought into conjunction, as Diamond et al. showed that hemolysis of red blood cells in the fetus to extramedullary erythropoiesis leads followed by hepatosplenomegaly and flood the bloodstream with erythroblasts, a state they called Erythoblastosis fetalis.