Thyroid Hormones and Moderate Exposure to Perchlorate during Pregnancy in Women in Southern California.

BACKGROUND: Findings from national surveys suggest that everyone in the United States is exposed to perchlorate. At high doses, perchlorate, thiocyanate, and nitrate inhibit iodide uptake into the thyroid and decrease thyroid hormone production. Small changes in thyroid hormones during pregnancy, including changes within normal reference ranges, have been linked to cognitive function declines in the offspring. [ABSTRACT FROM AUTHOR]