Hemolytic disease of the newborn
Hemolytic disease of the newborn (GBN) is a pathological condition that is accompanied by massive decay of red blood cells. This is due to incompatibility due to the Rh factor, blood type, or other rarer reasons. As you understand, the hemolytic disease of the newborn is a medical conflict between the mother and the baby. In that article, you will learn how GMD develops and how it is treated.
Rhesus conflict and HDN
Rhesus factor (Rh), in simple terms, is a specific protein (D-antigen). It is located on the surface of red blood cells. If it is present, then Rh + is absent, then Rh -. Rhesus conflict develops if the mother has a negative blood type, and the baby has a positive one.
When the red blood cells of the fetus penetrate the mother’s blood, they become antigens. The female body defines them as alien. Accordingly, antibodies begin to be produced. We observe an immune reaction that leads to various clinical manifestations.
Factors that increase the likelihood of HDN:
subsequent pregnancies and childbirth Rh-positive fetus (the risk increases by 8-10%),
organ and tissue transplantation,
signs of HDN in existing children.
According to statistics, 1 newborn out of 20-25 mothers with negative Rh has a hemolytic disease. This is due to several reasons, which are described below.
Protective function of the placental barrier
Normally, when the placenta during gestation passes no more than 0.1-0.2 ml of fetal blood to the mother. This amount does not contribute to the production of antibodies in women. They begin to be produced when the volume reaches 0.5 ml or more.
Increased permeability of the placental barrier occurs during delivery, placental abruption and pathologies during gestation. The latter includes: gestosis, diseases of the endocrine system, the threat of interruption, extragenital pathology, abnormalities in the development of the placenta and infection.
Protective factor for group incompatibility of blood
Rh incompatibility develops less frequently, with incompatibility in the blood group.
If an Rh-negative woman was born from an Rh-positive mother, then she develops tolerance to the D-antibody.
If the father is heterozygous Rh + Dd, then the risk of developing hemolytic disease of the newborn is reduced by 3-4 times.
Immunosuppressive state of a pregnant woman.
20-35% of Rh-negative people are unable to respond to D-antigen.
Incompatibility of blood groups (GK)
Not everyone knows that blood incompatibility can also contribute to the development of hemolytic disease in newborns. Conflict occurs in 10% of cases. Most often, GBN occurs if mom O (I) has a blood group, and baby A (II). This is due to the high activity of antigen-A and a higher titer of anti-A antibodies. The molecular weight of anti-A antibodies in people with O (I) HA is 5 times less than in B (III) HA.
If latent sensitization is triggered, then this can lead to HDN through the ABO system, even during the first pregnancy. Given the low molecular weight of anti-A antibodies, they easily pass through the placenta to the baby. This leads to the development of the disease.
Anti-A antibodies have a more damaging effect than Anti-B antibodies. In this case, the conflict is mild, in comparison with incompatibility with the Rh factor.
Protective processes associated with HDN
For sensitization, a pregnant woman needs a large amount of fetal blood.
Antigens A and B are found both in erythrocytes and amniotic fluid, placenta, fetal tissues. These conditions allow you to neutralize the antibodies of the mother.
The red blood cells of a child that enter the mother’s body are blocked by her own antibodies.
Forms of GBN
There are several forms of hemolytic disease of the newborn. Whatever the disease was provoked, the child himself suffers as a result of any conflict. Its immunological reactions destroy red blood cells, which leads to various symptoms. Their severity is proportional to the activity of the immune process. The earlier mother’s antibodies began to “host” the baby’s body, the more difficult the hemolytic disease is.
Forms of hemolytic disease of the newborn:
Edematous. It is considered the hardest. In this case, at birth, the baby has a general edematous syndrome. The skin and mucous membranes are pale, enlarged spleen and liver. Hemodynamic disturbances are observed. Jaundice may be mild or nonexistent. there is a risk of complications.
Anemic form is extremely rare and leaks easily. When the baby is born, pallor of the skin is observed, lethargy, weak sucking, heart sounds are muffled, systolic murmur. The liver and spleen can be of normal size, or slightly enlarged.
Jaundice or hemolytic jaundice of newborns. The most common. At birth or in the first few hours, jaundice, pallor of the skin and mucous membranes are manifested.