10/14/11

Thalassemia in Pregnancy - Organ Functions

 
Cardiac function and transfusion requirements

During pregnancy, the fluid component of the blood normally increases. This can increase the degree of anemia, which leads to the need for more frequent blood transfusions. Increased anemia can also result in the heart having to work harder to get adequate oxygen to all of the body's tissues. Increased blood volume can also put stress on the heart. In thalassemia, the heart may already be under stress from the damaging effects of iron overload. Therefore, it is important to have cardiac function checked prior to and throughout pregnancy. Regular attend-ance at scheduled transfusion appointments is also critical in order to reduce anemia and lessen the work that the heart must do.

Liver function

A liver biopsy may be indicated prior to pregnancy to assess the degree of iron overload. This information may be helpful in deciding whether or not to discontinue iron chelation. A liver biopsy can also help determine if there has been damage from iron deposition or previous hepatitis infection. Blood tests throughout pregnancy can also assess liver function.

Endocrine function

Individuals with thalassemia have an increased chance of developing insulin-dependent diabetes as a result of iron overload. The stress of pregnancy can worsen this condition, which can be detrimental to the health of the mother and developing baby. It is important to stabilize diabetes prior to becoming pregnant and to maintain adequate treatment throughout pregnancy. Thyroid function can also be impaired due to iron overload in the woman with thalassemia.

Splenic function

The spleen removes abnormal red blood cells from the circulation and performs important immune functions. Individuals who have thalassemia have unusually large numbers of abnormal red blood cells. The spleen becomes very active in removing these cells. This activity can enlarge the spleen making it more effective at removing even larger numbers or cells, causing a hemolytic anemia. During pregnancy, there is a greater need for hemoglobin both for normal growth and development of the fetus and due to the fact that the blood volume of the mother will increase dramatically. During this time, transfusion requirements in the pregnant woman is increased, particularly during the last trimester of pregnancy. If transfusion in adequate, the bone marrow will be suppressed and the work of the spleen can be decreased. Occasionally, this will lead to some decrease in spleen size and activity.

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