The Thyroid Blog

Contrary to Previous Studies, Low Levels of Perchlorate Exposure Are Safe For Pregnant Women, Say Endocrinologists

(Oct. 6, 2007) Despite great concerns that small amounts of ingested perchlorate—a chemical which is ever-present in the environment—decreases thyroid function among individuals, it has no effect on the thyroid function of women in early pregnancy, including those with a low-iodine diet, according to a new study being presented on Saturday, Oct. 6, at the 78th Annual Meeting of the American Thyroid Association (ATA) in New York.  Thyroid hormone is critical for the neurodevelopment of a fetus—particularly in the first trimester of pregnancy—and requires the mother to receive an adequate intake of iodine.

These findings are in contrast to last year's report from the Center For Disease Control and Prevention (CDC).

Small Papillary Thyroid Cancer Is More Common and Not Without Risk than Previously Believed

(Oct. 5, 2007) — Patients with micropapillary thyroid cancer—small tumors equal to or less than 1 centimeter—and tumors even smaller, less than 1 millimeter (mm)—are more common and not without a risk as previously thought, according to a new study presented on Fri., Oct. 5, at the 78th Annual Meeting of the American Thyroid Association (ATA) in New York.

This is contrary to the widely perceived belief that small papillary thyroid cancers are clinically insignificant and don't require active treatment. Papillary is the most common type of thyroid cancer, accounting for about 80% of all thyroid cancers.

The findings suggest that the size of the tumor itself may not be the sole determinant for the degree of the cancer's aggressiveness.

High TSH Levels May Cause Infants of Mothers With Under-active Thyroid To Have Visual Contrasting Problems

(Oct. 4, 2007) -- Children of women with hypothyroidism—an under-active thyroid—who had elevated thyroid stimulating hormone (TSH) in the first and second trimesters of pregnancy, had a significantly reduced ability to see visual contrasts, compared to women with hypothyroidism with normal TSH levels during the first two trimesters, and pregnant women with normal thyroid levels, according to a new study being presented on Thursday, Oct. 4, at the 78th Annual Meeting of the American Thyroid Association (ATA) in New York. Adequate contrast sensitivity is an important ability for reading, viewing information of low contrast such as maps, and visuospatial ability in general.

The study shows that visual processing problems among infants of women with hypothyroidism were directly correlated with the mothers' high level of TSH.  These findings suggest that thyroid hormone is critical in early pregnancy for normal development of visual processing abilities.

A previous study showed that infants born to women who had hypothyroidism diagnosed prior to or during pregnancy had reduced ability to see visual contrasts and that the severity of their deficit was related to how hypothyroid their mothers were during the pregnancy. 

Even Mild Thyroid Problems Double Risk Of Heart Condition

(Oct. 4, 2007)—Individuals with subclinical hypothyroidism—a mildly underactive thyroid only detectable by a blood test—are twice as likely to develop heart failure, compared to those with normal thyroid levels, according to a new study being presented on Thursday, Oct. 4, at the 78th Annual Meeting of the American Thyroid Association (ATA) in New York. Heart failure, also called congestive heart failure, is when the heart can't pump enough blood to the body's other organs, which can cause fatigue, ankle swelling and shortness of breath.

Although previous studies have shown that hyperthyroidism—an overactive thyroid—and hypothyroidism can cause heart problems, this is the first time that a large study found a negative effect on heart function when the thyroid was only mildly under-active.