Hemolytic disease in newborns (HDN, synonyms: fetal erythroblastosis, hemolytic anemia) is a disease manifested by massive destruction of red blood cells, the main cause of jaundice in a child, spontaneous abortion and stillbirth.
According to WHO statistics, the disease is detected in 0.6% of children, mortality is 2.5%. Pathology is associated with the immune system, because it is the result of a conflict of antigens of the blood of the mother and the fetus.
Factors causing hemolytic disease in newborns
It was revealed that all the main antigens are contained in red blood cells. A total of 6 Rh antigens were identified. One of them is the Rhesus factor, called D. antigen. It is the cause of incompatibility in 30% of the identified diseases, it is absent in the mother, and the fetus has inherited from the father. Therefore, antibodies are produced to it in the mother's body. This happens if the mother has Rhesus factor - negative, and in the child - positive.
In other cases, the disease is associated with antibodies that form blood groups (according to the ABO system). Hemolytic disease in newborns associated with group incompatibility develops when the mother has 0 (I) blood type, and in the fetus - A (II) or B (III).
Pathogenesis of the disease
The disease still develops in utero, its manifestations are different, but the result is erythrocyte hemolysis and death of the fetus (or newborn).
Hemolysis - This is the destruction of the erythrocyte membrane with the release of hemoglobin into the blood plasma. The erythrocyte destruction process itself is normal, because it happens every 120 days: this is how blood cells are updated. But during hemolysis, a huge amount of hemoglobin is released into the blood, as a result of which a high content of bilirubin and iron is formed in the blood plasma and the mechanism of the circulatory system is disrupted. In addition, anemia develops.
All this amount of hemoglobin enters the liver, where it is neutralized (conjugation with bile acids). With such a huge amount of released hemoglobin, the liver cannot cope with the load, and free bilirubin, which has neurotoxic properties, penetrates all organs, slows down oxidative reactions, causing destructive processes in tissues and organs at the cellular level, destroying them.
With a plasma content of 340 μmol / L bilirubin, it overcomes the blood-brain barrier, changing the structure of brain cells and leading to bilirubin encephalopathy. In the future, it leads to disability. For premature infants, the threshold concentration is 200 μmol / L. This occurs due to toxic indirect bilirubin damage to the nuclei of the base of the brain (subthalamic, hypocampus, cerebellum, cranial nerves).
Symptoms of hemolytic disease in newborns
Hemolytic disease in newborns occurs in three clinical forms:
• edematous;
• icteric;
• anemic.
The most severe form of the disease
The edematous form is characterized by the accumulation of fluid in the body cavities (pleural, abdominal and pericardial). There is an increase in the mass of the fetus and placenta by 2 times. An objective examination reveals:
• pallor of the skin and mucous membranes;
• hepato- and splenomegaly (a significant increase in the liver and spleen);
• bruising and petechiae on the skin.
In a general clinical blood test - severe anemia:
• hemoglobin - 30-60 g / l;
• red blood cells -1x1012 / l;
• correspondingly expressed anisocytosis, poikilocytosis, erythroblastosis;
• leukocytosis;
• neutrophilia with a pronounced shift to the left.
Such anemia in combination with hypoproteinemia and impaired capillary permeability causes severe heart failure, which is the cause of mortality of the fetus or newborn.
The most common form of hemolytic disease in newborns
Jaundice - The most common clinical form of the disease. It develops towards the end of pregnancy as a result of the effects of antibodies in the mother's body on the fetus. The mass of the child is not violated, the pregnancy proceeds normally, the child is born with normal skin color. In the future, the following manifestations develop:
• jaundice - the first symptom of the disease - occurs 1-2 days after birth; the intensity and color change as a result of the progression of the disease (orange - bronze - lemon - unripe lemon;
• hepato - and splenomegaly;
• pasty tissue in the lower abdomen;
• decrease in reflexes (sucking, swallowing), lethargy, adynamia.
In peripheral blood:
• anemia;
• pseudo-leukocytosis (due to an increase in young red cells, which are perceived as leukocytes when counted);
• an increase in reticulocytes.
In biochemical analyzes: indirect bilirubin - up to 350 μmol / l. It destroys hepatocytes, myocardial cells, selectively affects brain neurons. Excess bilirubin is deposited in the renal tubules, leading to kidney infarction. Bilirubin encephalopathy develops on the 5-6th day.
In connection with acute damage to the liver cells, the synthesis of proteins and blood coagulation factors is disrupted, which leads to a drop in prothrombin and an increase in bleeding. The viscosity and density of bile increases due to the high content, which leads to the formation of stones and the development of obstructive jaundice.
During the icteric form, several phases are distinguished:
1. intoxication in the form of lack of appetite, drowsiness, lethargy, decreased muscle tone, adynamia, vomiting;
2. effects on the nuclei of the brain - convulsive syndrome, decreased reflexes, bulging fontanel, neck muscle tension, nystagmus, decreased heart rate, apnea;
3. imaginary well-being - develops by 10-14 days of life, expressed in a decrease in pathological neurological symptoms, the disappearance of seizures;
4. complications - develop by 3-5 months of life in the form of paralysis, paresis, convulsions, deafness.
After a day, death can occur due to the toxic effects of bilirubin on the brain nucleus. Surviving children are significantly retarded from their peers in mental and physical development, have hearing and vision problems, low immune status, and therefore often suffer from various infections complicated by sepsis.
Anemic form
Anemic form develops in 15% of patients. It appears:
• lethargy;
• pallor;
• hepatolienal syndrome.
The pallor of the skin and mucous membranes is determined by 5-7 days, before that it is masked by yellowness.
Laboratory data:
• hemoglobin - 60-100 g / l,
• red blood cells - 2.5-3.0 T / l;
• reticulocytosis;
• bilirubin - a normal or slightly elevated level.
With this form of the disease, recovery quickly occurs when small amounts of Rh-negative blood are transfused.
Diagnosis and prevention of hemolytic disease in newborns
To determine the hemolytic disease in newborns, first of all, they study:
• the course of previous pregnancies;
• the presence of miscarriages or a stillborn child;
• lag in the development of existing children;
• Rhesus factor of the father of the unborn child.
Determination of antibodies in Rh-negative women. If they are, for the purpose of prevention, a specific anti-rhesus gammaglobulin is introduced, which weakens their aggressive effect.
In a future child, hemolytic disease is detected by analyzing amniotic fluid, which is extracted by amniocentesis. Suspicions of the existing pathology arise when bilirubin is detected and the specific gravity is increased.
Treatment principles
Treatment requires the immediate removal from the body of the dangerous products of hemolysis and the antibodies that led to it. At the same time, protection from the toxic effects of indirect bilirubin on the organs and systems of the child, the stimulation and maintenance of liver and kidney functions are necessary.
For this purpose, the following are used:
• transfusion of fresh blood;
• detoxification measures through the esophageal tube and parenteral;
• to improve the functions and protection of liver tissues - phenobarbital, ATP, methionine, xylitol, prednisone weekly course;
• vitamin therapy (vitamins of groups B, C, E);
• phototherapy - treatment with a blue lamp enhances the oxidation of indirect bilirubin, turning it into a non-toxic compound.
With timely treatment, the development of the child does not suffer. Modern perinatal centers have the ability to conduct intrauterine blood substitution of the fetus. This is possible with timely treatment and examination of a pregnant woman, her conscious approach to the health of the unborn child.
