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  • Polycythemia, or plethora, is a rare blood disorder occurring when there are too many red blood cells circulating in the bloodstream. The Anemia and Red Blood Cell Disorders Program at Boston Children’s Hospital provides comprehensive treatment and management of polycythemia.

    • Polycythemia is rare.
    • Babies with polycythemia have high red blood cell and hemoglobin counts.
    • Many babies with polycythemia have no visible symptoms.
    • Polycythemia is typically treated by withdrawing blood or replacing withdrawn blood with fluid.

    Boston Children's Hospital
    300 Longwood Avenue
    Boston MA 02115 

    617-355-8246 x2 

  • What is polycythemia? 

    Polycythemia, or plethora, is a blood disorder occurring when there are too many red blood cells, the parts of the blood that carry oxygen from the lungs to all parts of the body, circulating in the blood stream. This causes the blood to increase in volume and thicken, making it more difficult to flow through the body to the organs.

    What causes polycythemia?

    Polycythemia may be caused by:

    An increase in a baby’s red cell production due to:

    • chronically lowered oxygen levels
    • some chromosomal abnormalities

    Extra blood cells entering the baby's circulation due to:

    Is polycythemia common?

    Polycythemia is rare. Some babies may be at increased risk, including those born:

    • at high altitudes (greater demand for blood to carry oxygen)
    • after 42 weeks gestation
    • small for gestational age or with intrauterine growth restriction (poor growth of the baby while in the womb)
    • identical twins, who share a placenta and develop twin-twin transfusion symdrome
    • to diabetic mothers
    • with chromosomal abnormalities, including trisomies 13, 18 and 21 (Down syndrome

    What are the symptoms of polycythemia?

    Many babies with polycythemia have no visible symptoms of the disorder. When symptoms do appear, the most common are: 

    • deep reddish-purple coloring
    • poor feeding
    • tiredness
    • rapid breathing or distress
    • low blood sugar
  • How does a doctor know that it’s polycythemia?

    When a baby has polycythemia, blood tests show:

    • high hematocrit (red blood cell count)
    • high hemoglobin level (protein in red blood cells that helps them carry oxygen from the lungs to all the other parts of the body)
  • Treatments for polycythemia are delivered through a vein or artery, often the umbilical blood vessels, and may include:

    • withdrawing blood
    • replacing withdrawn blood with fluids
    • partial exchange transfusion to slowly remove and replace a large portion of the baby's blood volume
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