As you probably know, pregnancy often causes a low hematocrit in
women. In general, this can be considered to be an inaccurate
hematocrit reading, due to extra circulatory fluid and volume of a
pregnant woman. This is not to say an anemia in a pregnant woman is
insignificant, however. (The hemoglobin parameter is somewhat more
accurate when it comes to determining need for transfusion. Various
conditions can cause a hematocrit to be outside of a normal range;
hemoglobin is a more direct measurement of a patient?s oxygen carrying
capacity, not influenced by factors such as cell size and shape.)
Such tests as serum transferrin, ferritin, serum iron, and a serum
transferrin receptor are more accurate measurements of anemias, while
a hematocrit is used as a screening test.
Transfusion would be used to treat anemia, only as a last resort.
Transfusion, while increasingly safer, is still considered to be a
risk to mother and fetus. An iron-rich diet and iron pills would be
the first line of therapy, followed by iron dextran injections for
non-compliant or non-responding patients.
Criteria for transfusion will vary greatly, depending on the patient
and her obstetrician. A generally healthy woman would be less likely
to receive a transfusion during pregnancy than a woman with a chronic
disease or one who has been a trauma victim. In pre-AIDS/HIV days,
doctors often transfused patients with a hemoglobin of 10 or less.
(Roughly a hematocrit of 30). Today, that has been dropped to a
hemoglobin of 6-7, depending on the patient?s condition. (This equals,
roughly, a hematocrit of 18-21)
?For megaloblastic anemia due to folic acid deficiency, treatment is
folic acid 1 mg bid. Severe megaloblastic anemia may require
hospitalization for bone marrow examination and further treatment.
Anemias can be severe enough (Hb <= 6 g/dL) to require transfusion.?
?The amount of blood in your body increases 40 to 50 percent during
pregnancy. And when you're pregnant, your body needs more iron for
your developing baby, for the placenta, and to keep up with your
rapidly expanding blood volume. ?
?The Hct in women who are not pregnant is normally 38 to 45%, but in
pregnant women, normal values can be much lower (eg, 34% in a single
and 30% in a multiple pregnancy), even when stores of iron, folic
acid, and vitamin B12 are adequate. This lower range represents the
physiologic hydremia of pregnancy and does not indicate a decrease in
O2-carrying capacity or true anemia.?
?Anemia during pregnancy is defined as an Hb level of < 10 g/dL.
However, any patient with an Hb level < 11 to 11.5 g/dL at onset of
pregnancy must be treated as anemic, because the hemodilution that
occurs during pregnancy reduces the Hb level to the anemic range.
Anemia occurs in as many as 80% of some gravid populations.?
According to the American Association of Blood Banks,
?Although blood transfusion is rarely needed during pregnancy and
delivery, you may donate for yourself with the approval of your
physician and the blood bank medical director.?
?With regard to transfusions, this is normally not considered for
otherwise healthy persons as long as the hemoglobin level is above 8
grams per deciliter or the hematocrit is above 24%.?
?Transfusion decisions are based on the results of laboratory tests,
including hematocrit. Transfusion is not considered if the hematocrit
level is reasonable. The level differs for each person, depending on
his or her clinical condition.?
?Fluid volume in the blood affects the hematocrit. Pregnant women have
extra fluid, which dilutes the blood, decreasing the hematocrit.
Dehydration concentrates the blood, increasing the hematocrit.?
?And if these symptoms are severe or your hematocrit drops low enough,
you may even require a blood transfusion. (Anyone who loses a lot of
blood may need a transfusion, but the risk is higher if you're anemic
to begin with.) Finally, any anesthesia used ? if you end up having a
c-section, for example ? is riskier if you're severely anemic.?
Hope this has helped you understand anemia, transfusion, and
pregnancy. If any part of this answer is unclear, please request an
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H&h + preganancy
criteria for transfusing + pregnancy