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.

Anemia in Postmenopausal Women Linked With Poor Nutrition

Emma Hitt, PhD
Anemia is linked to poor nutrition in postmenopausal women, according to a recent observational study of the Women's Health Initiative (WHI).
Cynthia A. Thomson, PhD, RD, with the University of Arizona, in Tucson, and colleagues reported their findings in the April issue of the Journal of the American Dietetic Association.
According to the researchers, nutritional anemia includes those types associated with prolonged inadequate intake of folate, vitamin B₁₂, iron, protein, and vitamin C.
Dr. Thomson and colleagues hypothesized that a greater number of dietary inadequacies of these nutrients would be associated with a greater risk for incident and persistent anemia.
To evaluate their hypothesis, the researchers used data from the WHI observational cohort study (WHI-OS), which contained a longitudinal sample of postmenopausal women. A total of 93,676 postmenopausal women between the ages of 50 and 79 years were recruited at 40 clinical sites across the United States. Women were enrolled from 1993 until 1998, and data collection was completed in 2000.
Diet was assessed by a food frequency questionnaire for iron, vitamin B₁₂, folate, red meat, and cold breakfast cereal. Dietary intake for women older than 50 years was used as a reference to measure inadequacies. Anemia was defined as a blood hemoglobin concentration of less than 120 g/L in women. Persistent anemia was defined as anemia present at each measurement.
Anemia was identified in 3979 (5.5%) of the participants. Inadequate intake of anemia-associated nutrients was less frequent in non-Hispanic whites (7.4%) vs other racial or ethnic groups (14.6% - 16.3%).
Smoking, age, and body mass index were associated with anemia. Women with anemia reported a lower dietary intake of red meat, folate, vitamin B₁₂, vitamin C, and iron. In addition, deficiencies in dietary intake of 1 nutrient were associated with a 21% greater risk for persistent anemia (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.05 - 1.41), whereas 3 deficiencies in dietary intake resulted in a 44% increase in the risk for persistent anemia (OR, 1.44; 95% CI, 1.20 - 1.73).
Deficiencies in total intake of 1 nutrient were associated with a 34% increased risk for persistent anemia (OR, 1.34; 95% CI, 1.14 - 1.56). Regarding deficiencies in total intake of 3 nutrients, the risk increased to 56% (OR, 1.56; 95% CI, 1.25 - 1.95).
Editorial: Nutrient Measurements Costly
According to editorialists Lisa Tussing-Humphreys, PhD, RD, with the US Department of Agriculture–Agriculture Research Service, in Los Angeles, California, and Carol Braunschweig, PhD, RD, with the University of Illinois, in Chicago, this study provides "one of the largest prospective assessments of diet and anemia in US postmenopausal women."
They add that the findings "lend credibility to the use of an FFQ [food frequency questionnaire] for large epidemiological studies investigating the relationship between diet and anemia risk."
However, according to the editorialists, the mean nutrient intakes reported indicate that "a portion of the anemia observed in the WHI-OS cohort was not diet-related," they write. "For example, it is well known that decreases in hemoglobin occur from nutrient deficiencies only when stores are nearly exhausted."
In addition, although the accurate assessment of anemia allows clinicians to classify the type of anemia and recommend suitable treatment options, inclusion of these measurements in large epidemiologic studies is "cost-prohibitive and unlikely."