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Polycythemia in the Newborn
Polycythemia is an abnormally high
concentration of red blood cells.
This disorder may result from
postmaturity (see see Problems
in Newborns: Postmaturity), diabetes in the mother, or a low oxygen level in
the fetal blood.
A high concentration of red blood cells makes the blood
thick (hyperviscosity) and may slow blood flow through small blood
vessels.
Most affected newborns do not have symptoms but
occasionally have a ruddy or dusky color, are sluggish (lethargic), feed poorly,
and very rarely may have seizures.
The diagnosis is inferred from a test that measures the
content of red blood cells in the blood.
Usually no treatment is needed except to maintain normal
hydration.
When the newborn has symptoms, treatment with a partial
exchange transfusion may be given to reduce the red blood cell
concentration. A markedly increased concentration of red blood cells may result
in the blood being too thick, which slows the flow of blood through small blood
vessels and interferes with the delivery of oxygen to tissues. A newborn who is
born postmaturely or whose mother has diabetes, has severe high blood pressure,
smokes, or lives at a high altitude is more likely to have polycythemia.
Polycythemia may also result if the newborn receives too much blood from the
placenta at birth, as may occur if the newborn is held below the level of the
placenta for a time before the umbilical cord is clamped. Other causes include a
low oxygen level in the blood (hypoxia), maternal diabetes, growth restriction
in the womb, or a large transfusion of blood from one twin to another
(twin-to-twin transfusion).
A newborn with severe polycythemia has a very ruddy or dusky
color, is lethargic, feeds poorly, and may have seizures. If the newborn has
such symptoms, and a blood test indicates too many red blood cells (high
hematocrit), some of the newborn's blood is removed and replaced with an equal
volume of saline solution, thus diluting the remaining red blood cells and
correcting the polycythemia. |