What Is Hemolytic Disease Of The Newborn?
What is hemolytic disease of the newborn? Here`s a question that shouldn`t go unanswered if you are going to be a future mother. This is a medical condition that may involve your future baby, so staying well informed is a must in this situation.
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What Is Hemolytic Disease of the Newborn?
Hemolytic disease, also known as fetal erythroblastosis or HDN, represents a blood disorder which affects the newborn in Rh incompatibility with his mother. The illness is diagnosed when the baby is born, because it occurs when pregnant women don`t perform blood tests to determine the blood group and Rh. The consequences of this medical condition can be quite severe: jaundice and pronounced anemia. Find out more about hemolytic disease, its causes and symptoms, as well as how the condition can be treated.
- “hemolytic” means destruction of red cells.
- “erythroblastosis” means the production of immature red cells.
- “fetal” refers to the fetus.
HDN occurs most frequently when a mother with negative Rh has a child with a father who has positive Rh. When the child has positive Rh, the same as his father, the issues may appear when the red blood cells in the baby`s blood reach the mother with the negative Rh. Usually, this happens at birth when the placenta detaches. Still, it may also happen for the blood cells to mix (between the mother and fetus), like during an abortion or an invasive prenatal testing (e.g. biopsy of coronary villitis or amniocentesis).
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The mother`s immune system recognizes the Rh-positive cells as “foreign.” Just as when a bacterium invades the organism, the immune system tries to fight back by developing antibodies to destroy the foreign cells. The mother`s immune system keeps the antibodies just in case these foreign cells “think” of reappearing, even if we talk about a future pregnancy. From that particular moment on, the mother is “sensitized Rh.”
Although not so common, a rather similar issue of incompatibility might appear between the mother and fetus groups (A, B, O, AB) in the following cases:
|Mother`s blood group||0||A||B|
|Fetal blood group||A or B||B||A|
In a first pregnancy, Rh sensitization in unlikely. Usually, this becomes a problem for a future pregnancy with a baby with positive Rh, the mother`s antibodies traversing the placenta and fighting with the baby`s positive Rh cells. Since antibodies destroy the red blood cells of the fetus, this may get sick. As already mentioned, this medical condition that occurs at birth is known as fetal fetal erythroblastosis. In newborns, the illness is known as hemolytic disease of the newborn.
Group AB0 Incompatibility
In ABO incompatibility, the mother has the blood group O, while the fetus can be A, B, AB. A bit more rarely, the mother has B blood and fetus A. Maternal-fetal group incompatibility is considered the most common cause of neonatal jaundice.
Hemolytic disease isn`t seen in premature babies under 36 weeks and manifested after birth, thus pregnancy isn`t interrupted in advance and intrauterine transfusion interventions aren`t available, with the illness having an evolution that is easier than Rh incompatibility.
When older generations were concerned, Rh incompatibility was a particularly severe health issue. Fortunately, modern medicine have managed to prevent such medical complications that result from Rh incompatibility and the treatment of infants affected by this illness, and at present it rarely occurs in medical practice. A child born and diagnosed with this disease has increased abdomen and liver, might have circulatory and respiratory insufficiency, pronounced jaundice and serious anemia.
HDN – Differences between the First and Second Pregnancy
This diseases is more rarely encountered in the first pregnancy of a mother with negative Rh. However, starting with the second pregnancy, the fetus may experience problems of incompatibility of Rh with his mother and may be affected by HDN.
If you may be wondering why the first baby with positive Rh born by a mother with negative Rh is safe from this medical condition, the answer is that in the first pregnancy takes place the immunization of the mother to the baby`s blood. Antigen D, present in the child`s blood and triggering factor of the immunological war between the mother and her baby, “will take by surprise” the mother`s organism at first exposure – the organism will fight with weak weapons against the antigen (the number of antibodies is very low).
At the second exposure (second pregnancy), the mother`s organism will be immunized and, therefore, will increase the risk of HDN in the child.
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It`s good to know that, once immunized, the mother`s organism stays this way throughout the entire life. This means that the next children can all be born with this disease. The number of antibodies produced by the mother`s organism will increase in the next pregnancy.
Also, if at the second pregnancy (with a baby still found in Rh incompatibility with his mother) the mother wasn`t immunized, she won`t ever by immunized, no matter how many children she`ll have.
This disease can be traumatic for both the child and parents, but with a lot of care, the baby can overcome this dilemma.
The diagnosis of this medical condition can be made before pregnancy by screening the antigens present in the blood of the mother.
During pregnancy, an ultrasound is the most conclusive option. Therefore, blood flow can be measured and certain issues that may appear in the fetus can be outlined.
The doctor who supervises the women`s pregnancy is aware of her Rh as well as the one of the father, so these specific tests that follow hemolysis and the fetal status will be asked.
After birth, the analysis of the umbilical cord will be performed.
Why Is HDN a Reason of Concern?
When the mother`s antibodies attack the red blood cells, these are destroyed (hemolysis). This brings anemia to the baby. Anemia is a dangerous medical condition because it limits the blood`s ability of transporting oxygen in the baby`s organs and tissues. Therefore:
- The baby`s organism responds to hemolysis by attempting to produce (in a shorter period of time) more red blood cells in the bone marrow, spleen and liver. This leads to the development of organs. The new cells, known as endobalts, are frequently immature and, therefore, unable to replace all the functions of red cells that were mature.
- As the red blood cells decompose, it`s formed a new substance known as bilirubin. Babies aren`t able to get rid of it and, thus, it may accumulate in the blood, tissues as well as other of the baby`s organs. This particular medical condition is known as hyperbilirubinemia. Because bilirubin contains a coloring pigment, there`ll be a yellowing of the baby`s skin and tissues. This latter illness is known as jaundice.
Complications of this disease might vary from medium to severe. The following consists some of the issues which might arise from this particular medical condition:
- Mild anemia, hyperbiliruvinaemia, jaundice.
- Hydrops fetalis.
- The placenta aids eliminate some bilirubin, however, not all.
- Serious anemia with enlarged spleen and liver.
- This condition occurs from the child`s organs` inability of controlling anemia. The heart starts failing and the fluid amount in the organs and tissues of the child increases. A hydrops fetus has an increased risk of dying.
- Severe jaundice and hyperbilirubinemia.
- Nuclear jaundice.
- The liver of the child cannot control the bilirubin`s large amount that results from the destruction of red blood cells. The baby`s liver is increased and anemia continues.
- Nuclear jaundice is the most serious form of hyperbilirubinemia and is caused by the accumulation of bilirubin in the brain. This can lead to seizures, deafness, brain injuries as well as death.
Before birth, treatment options include intrauterine transfusions or early induction or labor – when pulmonary maturity was reached, when fetal suffering is present, if 35 – 37 weeks of pregnancy has passed.
The mother may receive a blood transfusion to reduce the levels of antibodies.
After birth, the treatment depends on the severity of the condition. This may involve the following measures:
- Temperature stabilization.
- Careful monitoring.
- Compatible blood transfusions.
- Exsanguine transfusion with a type of blood compatible with both the baby and mother.
- Sodium bicarbonate for acidosis correction
- Assisted ventilation.
Mothers get immunoglobulin at 28 and 34 weeks of pregnancy and 72 hours after delivery for preventing sensitization to antigen D.