Morbus haemolyticus neonatorum is a serious pathological disorder of the unborn child and the newborn. It is caused by rhesus incompatibility.
What is haemolyticus neonatorum disease?
Morbus haemolyticus neonatorum is also called fetal erythroblastosis or fetopathia serologica. The disease usually occurs before birth and is therefore also called haemolyticus fetalis. Due to blood group incompatibility, the child develops anemia while still in the womb. The entire organism does not receive enough oxygen. The heart is not fully functional and effusions occur in the abdominal cavity and chest. If the disease is detected early, the child can be treated by blood transfusion in the womb. Rhesus incompatibility as a cause is prevented in Germany by giving antibodies against the Rhesus blood group trait to all mothers with negative Rhesus factor.
Causes
The main cause of haemolyticus neonatorum is rhesus incompatibility. Rhesus factor is a surface protein found on the cell surface of red blood cells (erythrocytes). If a person has the rhesus factor D antigen, he or she is rhesus positive. If a person lacks this antigen, he or she is Rh negative. When a person with negative rhesus factor has contact with rhesus-positive blood, the body forms antibodies to the rhesus factor D antigen. Since the body does not know this antigen from its own blood, it considers it foreign and fights it. During childbirth, blood usually passes from the newborn to the mother. If the child is rhesus-positive and the mother is rhesus-negative, she develops antibodies against the rhesus D antigen. This is usually the first antigen sensitization. Thus, the first child is usually not affected by haemolyticus neonatorum. In rare cases, a transfer of fetal erythrocytes into the maternal blood already occurs during the first pregnancy. Antibodies are also formed in this case. Since the amount of red blood cells that are washed into the mother’s blood and thus the amount of antibodies formed is rather small, they are not sufficient to cause haemolytic neonatal disease in the firstborn. In a second pregnancy with a rhesus-positive child, the mother’s antibodies against the rhesus factor D antigen reach the unborn child via the placenta. Since the antibodies are hemolytically active, i.e., they destroy the red blood cells, the child develops hemolysis. Due to hemolysis, anemia develops. Another cause of haemolyticus neonatorum is AB0 incompatibility. It is based on the same principle as rhesus incompatibility.
Symptoms, complaints, and signs
The disease begins to show symptoms in the womb. The fetuses deposit more water into the tissues, causing effusions in the abdominal cavity and pleural cavity. The accumulation of water in the abdominal cavity is also known as ascites. There is a marked increase in amniotic fluid. As soon as an amniotic fluid index (AFI) of more than 20 centimeters is present, it is polyhydramnios. In the womb, the pumping weakness of the heart is also already evident. When all the symptoms of haemolyticus neonatorum are fully developed, the complete picture (hydrops fetalis) is present. Anemia may be diagnosed after birth. The edema is clearly visible. The infant’s abdomen is distended due to the edema. Severe neonatal jaundice (icterus neonatorum) may also be observed.
Diagnosis and course of the disease
Already in early pregnancy, blood grouping is performed as part of prenatal care. In addition, an antibody screening test for irregular blood group antibodies is done. If the result of the antibody search test is negative, the test is performed again in the 25th to 27th week of pregnancy. Based on regular ultrasound screening, developing hydrops fetalis can be detected early. If haemolyticus neonatorum is suspected, blood can be drawn via the umbilical cord. In this way, anemia can be diagnosed. After birth, the Coombs test is performed in the laboratory. This test can detect incomplete antibodies, called IgG, against erythrocytes. In order to be able to record the extent of the damage to the blood cells, hemolysis parameters such as reticulocytes or LDH are determined in the laboratory.Reticulocytes are precursors of erythrocytes. Since the body produces more erythrocytes to compensate for anemia, more reticulocytes are found in the blood of the newborn. LDH, L-lactate hydrogenase, is an enzyme found in all cells. As a laboratory parameter, it indicates cell damage, in this case damage to erythrocytes.
Complications
In most cases, haemolyticus neonatorum disease causes various symptoms and complications even before birth. Those affected suffer from water retention that is located directly in the abdominal cavity. It is also not uncommon for the patient’s heart to be affected by haemolyticus neonatorum, so that it only shows a weakened pumping capacity. In the worst case, this can lead directly to the death of the patient if heart failure occurs. Similarly, the so-called neonatal jaundice can set in after birth. In most cases, haemolyticus neonatorum can be diagnosed before birth, so that treatment can be initiated immediately after birth. This usually does not lead to further complications. With the help of medication and therapy, the symptoms can be limited. In most cases, the course of the disease is positive and the patient’s symptoms are completely limited by the treatment. The life expectancy of the patient is also not reduced by haemolyticus neonatorum. However, in some cases, affected individuals are dependent on blood transfusions.
When should you see a doctor?
Pregnant women should generally attend the preventive and check-up examinations offered during pregnancy. In this way, the current state of health of the fetus is checked and documented. If changes and abnormalities nevertheless occur outside of the checkup appointments, an additional visit to the doctor is advisable. If the expectant mother has a vague feeling that something might be wrong with her health or the development of the growing child, a doctor is needed. Changes in the appearance of the skin, an inner restlessness, palpitations, sleep disturbances or feelings of insecurity should be discussed with the attending physician. Swelling, a large unusual weight gain or a general feeling of malaise should be clarified by a physician. If, despite all the examinations and checks that have taken place during pregnancy, no abnormalities can be detected, the newborn child is examined independently by the obstetric team immediately after delivery. In the first routine postnatal tests, midwives or attending physicians detect any existing irregularities in the infant’s health. Parental intervention is not necessary. Disturbances of the heart rhythm, discoloration of the skin or swellings on the body are noticed by visual contact with the newborn and in initial examinations to determine bodily functions. If there is a need for action, further tests are performed and responsible physicians are informed. This happens automatically in the case of an inpatient birth or a birth attended by a midwife.
Treatment and therapy
If haemolyticus neonatorum develops during pregnancy, blood transfusions can be given via the umbilical cord. With early therapy, hydrops fetalis can be avoided. In half of all newborns with rhesus incompatibility, only neonatal icterus is present. This usually does not require treatment. Phototherapy may be performed. This involves illuminating the child with light from the blue range. The unconjugated bilirubin, which causes the yellowing of the skin, is thereby converted into water-soluble bilirubin derivatives. These can be excreted without problems. In the other half of the newborns, severe jaundice is present, which must be treated with blood exchange transfusions. In individual cases, the administration of immunoglobulins can alleviate the hemolytic symptoms. The full-blown case of haemolyticus neonatorum, hydrops fetalis, is an emergency that must be treated in the intensive care unit. Infants are intubated and artificially ventilated.
Outlook and prognosis
The sooner the risk of the disease haemolyticus neonatorum can be detected, the better the chance of recovery.In most of the affected children, the disease subsides without therapy or already through the use of a special light therapy. However, in some particularly severe cases, the disease can develop to a life-threatening extent, especially if no appropriate treatment is given. Then there is the danger that affected children can die from the complications of the disease. If left untreated, the increasingly progressive hemolysis, after delivery, leads to dangerous hyperbilirubinemia, which can result in damage to the body from indirect bilirubin. In particular, muscle weakness in the newborns already indicates the onset of encephalopathy. With increasing damage to the brain, patients develop seizures as well as generalized spasticity. Respiratory insufficiency and pulmonary hemorrhage often accompany the disease. About 25 percent of affected fetuses develop signs of marked anemia, with a dangerous hemoglobin concentration below 8 g/dL, as a result of the anti-D as early as the 18th to 35th week of pregnancy. Without treatment, this leads to acidosis, hypoxia, splenomegaly and liver damage. This in turn leads to massive edema tendency in the affected fetuses. Other complications such as pulmonary edema and pulmonary hemorrhage can also lead to early death.
Prevention
For prevention, rhesus-negative pregnant women are injected with anti-D immunoglobulin at 28 weeks’ gestation and after the birth of a rhesus-positive baby. The antibodies bind to the erythrocytes transferred from the child. The affected erythrocytes are broken down in the mother’s spleen before the mother’s immune system can make its own antibodies.
Follow-up
In haemolyticus neonatorum, follow-up measures are usually significantly limited. It is a congenital disease that cannot be completely cured. For this reason, the affected person should see a doctor at an early stage to prevent the occurrence of other complications and symptoms. It is also not possible to cure the disease on one’s own. If the affected person wishes to have a child, he or she should first and foremost have a genetic examination and counseling in order to prevent a recurrence of Morbus haemolyticus neonatorum. Affected individuals are dependent on phototherapy in many cases. In many cases, the help and support of one’s family in this disease is also very important. Psychological support also has a very positive effect on the further course of the disease and can limit depression and other psychological complaints. Here also the contact to other patients of Morbus haemolyticus neonatorum can be meaningful, since it comes thereby to an exchange at information, which can facilitate the everyday life of the concerning.
What you can do yourself
The therapy of the Morbus haemolyticus neonatorum must take place compellingly on a pediatric intensive care unit by experienced personnel. A feeling of helplessness quickly arises in parents of young patients. Seeing one’s own child in the midst of tubes and machines evokes unwanted negative emotions, dominated above all by fears. Many clinics offer professional emotional support in such moments, which can help to better cope with the stressful experience. It is important to involve both partners and, if necessary, also siblings and to discuss feelings openly with each other. However, the real patient is and remains the sick child. More than anything else, it needs the closeness and attention of its parents during this difficult time. Therefore, whenever possible, both partners should participate in the care of the newborn and also communicate this wish to the professional care team. As a rule, this request is gladly complied with. Regular contact with the parents is proven to contribute to the child’s health and effectively combats the child’s own sense of powerlessness.
