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Premature Baby
Premature Baby-Anemia
 Anemia
is a deficiency of the red blood cells required by the body to carry hemoglobin.
Hemoglobin is necessary because it carries oxygen through the blood into all
parts of the body keeping it alive. Hemoglobin levels should be higher than 15
grams or it is considered too low.
Low levels of
red blood cells are quite common among premature babies, and many times preemies
under 1,000 grams (especially) require a transfusion of red blood cells. There
are a many reasons why a premature baby may develop anemia. First of all, during
the first few weeks of life premature babies' bodies do not make many new red
blood cells, and the red blood cells their bodies do have do not last as long as
older children.
Blood loss is
another reason that a premature baby can become anemic. Premature babies can
have bleeding problems that can increase their risk of developing anemia, and
one serious problem is Intraventricular Hemorrhage (IVH). A premature baby can
also develop anemia if her blood is drawn too frequently.
Studies are
being done on iron supplements for premature babies, and how they will be
administered if they are found to be effective. Right now transfusions are the
best and safest way to increase the iron in your premature baby's blood.
Symptoms of anemia (low iron in the blood) are pale skin, lethargy, poor feeding,
tachypnea, and tackycardia.
By Sjona
Lindquist
Diagnosis of Anemia of Prematurity
 In
adults and babies alike, new red blood cells are constantly being produced
and old ones broken down in the body. The production of red blood cells (RBCs)
is initiated by a
hormone
called
erythropoietin
or EPO. When a premature baby is born, the production of EPO tends to drop
off slightly and there is a corresponding drop in the production of RBCs.
This process is the cause of the condition known as the physiological
anemia of
infancy.
Since the
production of RBCs happens in cycles and newborn babies are only beginning
this cyclical process, diagnosing anemia is not as simple as counting RBCs
in a blood test. Typically, a premature baby will have a normal drop in RBCs
a few days or weeks after birth. Additionally, premature babies often need
to have blood taken for other tests, sometimes frequently. Although the
amount of blood taken from a newborn baby will be the absolute minimum,
anemia can be caused or can be made more severe simply by this process of
taking blood.
How anemia of prematurity is
diagnosed
Over a period
of weeks, a premature baby with anemia of prematurity will likely appear
pale and lethargic, though occasionally there will be no symptoms.
Blood work
will be obtained, specifically a
hemoglobin
level and a reticulocyte count, which gives an indication of how fast RBCs
are being produced and released from the
bone marrow.
 Anemia
can have several causes, including sudden blood loss, increased destruction
and reduced production of RBCs, and so other tests will be done to determine
the specific cause of a baby’s anemia. Increased destruction of RBCs may
occur if the mother and baby’s blood groups are not compatible. This process
is known as hemolysis and the condition is called hemolytic anemia. Other
causes of hemolysis include abnormally shaped RBCs and missing enzymes
within the RBC. Reduced production of RBCs may be
acquired
due to a lack of iron or vitamins B6 or B12.
At times, it may just be that the baby is undergoing a period of rapid
growth and the production of RBCs has yet to catch up with the increasing
size of the baby’s body. The very rare
congenital
anemias are another cause of reduced RBC
production.
Diagnosis of Anemia of Prematurity
In adults
and babies alike, new red blood cells are constantly being produced and
old ones broken down in the body. The production of red blood cells (RBCs)
is initiated by a
hormone
called
erythropoietin
or EPO. When a baby is born, the production of EPO tends to drop off
slightly and there is a corresponding drop in the production of RBCs.
This process is the cause of the condition known as the physiological
anemia
of
infancy.
Since the
production of RBCs happens in cycles and newborn babies are only
beginning this cyclical process, diagnosing anemia is not as simple as
counting RBCs in a blood test. Typically, a premature baby will have a
normal drop in RBCs a few days or weeks after birth. Additionally,
premature babies often need to have blood taken for other tests,
sometimes frequently. Although the amount of blood taken from a newborn
baby will be the absolute minimum, anemia can be caused or can be made
more severe simply by this process of taking blood.
Treatment of Anemia of Prematurity
 Anemia
is a condition in which the body
does not produce enough red blood cells (RBCs).
The best
way to treat anemia is to create conditions that reduce the likelihood
of its development. To help prevent anemia, the smallest possible amount
of blood is taken from a premature baby whenever a blood test is needed.
Additionally, optimal nutrition can decrease the likelihood that an iron
or vitamin deficiency will occur. Supplemental iron will likely also be
administered once the baby is a few weeks old.
If anemia
does occur, these two strategies will continue but may be augmented by
other treatments. The decision to provide additional treatment is
influenced by the
gestational age,
birthweight, postnatal age, and general condition of the premature baby.
Additional treatment may not be necessary, especially if the anemia is
mild and there do not appear to be any adverse effects for the premature
baby.
On the
other hand, a
blood transfusion
may be recommended. Generally speaking, while blood transfusion has the
immediate effect of increasing RBC levels, it also often has the effect
of suppressing the baby’s
erythropoietin
level. Erythropoietin is a
hormone
which stimulates the production of RBCs, so when the transfusion
suppresses erythropoietin, it slows down the ongoing production of RBCs.
However, the baby will usually begin producing his own erythropoetin
shortly after the blood transfusion.
Blood for
transfusion is cross-matched to avoid blood group incompatibility
between the donor and the premature baby. The blood is carefully
screened for the
hepatitis A,
B, and C
viruses,
cytomegalovirus,
and human immunodeficiency
virus (HIV)
to minimize the likelihood of transmission of a viral
infection.
In many
hospitals, it is possible for the premature baby’s parent to make a
directed donation to the baby. The parent and baby must have compatible
blood groups, and the parent’s blood must be free of infection. A
directed donation is no safer than a donation from any other suitable
donor.
 A
drug called a diuretic, which causes an increased urine output, may be
given during or shortly after a blood transfusion if there is concern
that the baby is experiencing fluid overload. There is no need to give a
diuretic routinely with a blood transfusion. Furosemide is the most
commonly used diuretic.
Since the
physiological anemia of
infancy
occurs as a result of a lack of
erythropoietin, there has been considerable interest in giving
supplemental erythropoietin to premature babies. Supplemental
erthyropoetin is generally given by injections under the skin one to
three times a week for a period of four to six weeks. RBC production
increases and the impact of the physiological anemia of infancy can be
reduced. However, blood transfusions are still required, especially
during the first few days of life.
Although
erythropoietin is not used routinely for the treatment of anemia of
prematurity, it may be useful in special circumstances. Erythropoietin
may make a valuable contribution to the care of those premature babies
whose parents are Jehovah Witnesses, who usually refuse blood
transfusions on religious grounds
Reviewed by
Andrew James, BSc, MBChB, FRACP, FRCPC.
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