Introduction
Neonatal polycythemia is an abnormal level of red blood cells (RBCs) in newborn infants. Hemoglobin levels above 65 percent or venous hematocrit levels above 22 grams per decilitre indicate polycythemia in newborns. As a result, there may be decreased blood flow, decreased oxygenation of the tissues, and susceptibility to microthrombi formation, which may be aggravated by hypoxia, acidosis, or poor perfusion. Its incidence is said to range from one to five percent. The risk of neonatal polycythemia is higher in infants born to women living in high altitudes.
What Is Polycythemia?
Polycythemia is defined as a rise in the number of red blood cells in the body. The additional cells thicken the blood, increasing the risk of serious health problems such as blood clots.
A variety of factors can cause this condition. Polycythaemia can be classified into numerous kinds based on the underlying reason. In certain circumstances, the fundamental cause cannot be determined. Absolute polycythemia is described as an increase in the count of red blood cells. It can be due to genetic changes in the bone marrow (primary polycythemia), physiological changes brought on by one's environment, drugs, or other medical problems. Relative polycythemia refers to a reduction in the volume of plasma in the blood, making it thicker.
What Is Neonatal Polycythemia?
Neonatal polycythemia is defined by venous hematocrit (HCT) or hemoglobin much higher than normal levels for gestational and postnatal age. This disease affects one to five percent of neonates. Although many affected newborns are asymptomatic, the typical clinical symptoms are assumed to result from hyperviscosity and the metabolic implications of increased red blood cell volume. Hemoglobin, a protein found in red blood cells, provides red color to blood and enables it to transport oxygen from the lungs to all body tissues. Cells use oxygen to produce the body's necessary energy, leaving carbon dioxide as a waste product. Carbon dioxide is transported back to the lungs by red blood cells from the tissues. The blood may become excessively thick if there is a considerably elevated concentration of red blood cells. Excessive blood thickness restricts blood flow through tiny blood vessels and obstructs oxygen delivery to tissues resulting in complications.
What Are the Causes of Neonatal Polycythemia?
An infant is more likely to suffer polycythemia if the mother lives in high altitudes, has diabetes, has severe high blood pressure, or is a chronic smoker. Polycythemia can also develop if the newborn receives too much blood during birth from the placenta, which connects the fetus to the uterus and feeds it. This can happen if the infant is kept too long below the placenta's level before the umbilical cord is tied. The other causes of neonatal polycythemia are the following.
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Low oxygen in the blood (hypoxia).
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Congenital disabilities.
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Twin-to-twin transfusion syndrome (blood transfusion from one twin to another).
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Genetic conditions.
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Birth injuries.
What Are the Symptoms Associated With Neonatal Polycythemia?
Around 74 to 90 percent of babies born with neonatal polycythemia are asymptomatic. Neonatal polycythemia can have an impact on a variety of organs and systems. Clinical symptoms are caused by hyperviscosity, a reduction in tissue perfusion, and metabolic consequences such as hypoglycemia and hypocalcemia. Apnea, cyanosis, feeding difficulties, vomiting, restlessness, lethargy, respiratory distress, and seizures are the non-specific signs and symptoms of neonatal polycythemia. Central nervous system diseases are the most typical complication in babies with severe polycythemia. Cardiopulmonary complications, along with tachypnea and tachycardia, may also develop in affected infants. Renal problems seen in neonatal polycythemia are proteinuria, decreased glomerular filtration rate, and renal vein thrombosis.
What Are the Tests Used for the Diagnosis of Neonatal Polycythemia?
The newborn undergoes a blood test to determine if they have polycythemia. A blood test to count the RBCs will be performed if the infant exhibits hyperviscosity symptoms. It is known as a hematocrit test. Other tests used for the diagnosis of neonatal polycythemia are the following.
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Blood sugar level.
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Creatinine level.
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Oxygen level in the blood.
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Bilirubin levels.
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Blood urea and nitrogen levels.
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Urinalysis.
What Is the Treatment for Neonatal Polycythemia?
All neonates with polycythemia should be examined and monitored for any signs of neurologic, gastrointestinal, or cardiac issues and often-occurring problems, including hypoglycemia and hyperbilirubinemia. The management of neonatal polycythemia depends on two factors. The presence of suggestive symptoms of polycythemia and absolute hematocrit value. A partial exchange transfusion (PET) is the only effective treatment for polycythemia. To do PET, some blood volume must be removed and replaced with fluids to lower the hematocrit to the desired 55 percent packed cell capacity. Even after a partial exchange transfusion, symptoms like jitteriness (frequent involuntary movements) could last a couple of days even though the hematocrit has dropped to physiological levels. The volume of blood exchanged is calculated based on the given formula.
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The Volume of Exchange = Blood volume x (Observed hematocrit –Desired hematocrit) / observed hematocrit.
What Are the Complications of Neonatal Polycythemia?
Neonatal polycythemia may cause complications due to the hemodynamic and metabolic effects of hyperviscosity, decreased organ blood flow, microcirculatory hypoperfusion, multisystem organ dysfunction, and destruction of increased erythrocyte mass. The possible complications of neonatal polycythemia are seizures, kidney failure, stroke, reduced motor response, and necrotizing enterocolitis.
Conclusion
Neonatal polycythemia is an abnormal increase in the number of red blood cells in newborns. It can be caused by prematurity, twin-to-twin transfusions (in which blood flows from one fetus to the other), diabetes in the mother, or a low oxygen level in the fetus's blood. A large quantity of red blood cells thickens the blood (hyperviscosity) and may delay blood flow via small blood vessels. Most of the affected neonates do not show any symptoms, but they may have a reddish or dark complexion, feed poorly, be lethargic, and, in rare cases, experience seizures. The diagnosis is based on a test that counts the number of red blood cells in the blood. Except for fluid administration, no therapy is usually required. When the infant exhibits symptoms, a partial exchange transfusion may be administered to lower the concentration of red blood cells.
