Controversial Chemical Fine for Pregnant Women
Reported October 08, 2007
(Ivanhoe Newswire) — Small amounts of ingested perchlorate — a chemical widely found in foods and drinking water — has no effect on the thyroid function of women in early pregnancy, including those with a low-iodine diet. These findings are contrary to those reported last year by the Centers for Disease Control and Prevention (CDC).
Perchlorate is both naturally occurring and man-made, found in small amounts in the environment. Ingesting the chemical can decrease thyroid function, but the thyroid hormone is critical for the neurodevelopment of a growing fetus, especially in the first trimester of pregnancy.
The CDCs report last year showed perchlorate exposure slightly decreased thyroid function in women with a low iodine diet, but not in men or women with a normal iodine diet. However, these most recent findings do not support the CDCs report.
In a large study of first-trimester pregnant women, which is a potentially vulnerable population, we found no effect of environmental perchlorate exposure on thyroid function, even though the amount of perchlorate in the urine was similar to that found in the U.S. population. About 70 percent of the women were mildly iodine deficient, Elizabeth N. Pearce, M.D., lead author of the study from Boston University School of Medicine in Boston, was quoted as saying.
Previous findings concerned communities, doctors and the Environmental Protection Agency (EPA) because thyroid hormone deficiencies in expectant mothers could cause behavioral changes, delayed development and decreased learning capability in newborns.
Study authors say this confounding evidence suggests prior findings linking thyroid function test alterations associated with perchlorate intake may not be justified.
SOURCE: The 78th Annual Meeting of the American Thyroid Association in New York, October 4-7, 2007