Maternal Thyroid Problems and Lowered IQ in Children

It has been known for over 100 years, that thyroid problems during pregnancy can cause problems in the cognitive development of the children. Even mild thyroid problems in pregnant women can lead to a permanently lowered IQ in their children.

Perchlorate is a chemical that is produced by both natural and man-made processes. It is a substance that has been shown to interfere with iodine uptake by the thyroid gland which can cause hypothyroidism. There is no known therapeutic use of perchlorate. It is an inhibitor of the sodium-iodide symporter that is responsible for transporting iodine into the glandular tissues including the thyroid and the breast. In other words, perchlorate exposure can inhibit the ability of iodine to be transported into the thyroid or the breast tissue as well as other endocrine glands.

Artificially produced perchlorate occurs during many manufacturing processes including the production of fireworks, rocket fuel herbicides and bleaching agents. Too much perchlorate can contaminate the soil and water. Low levels are perchlorate are known to contaminate water sources. Over four percent of our water supply is known to be contaminated with perchlorate especially in the U.S. West around Las Vegas and California.

Researchers studied 487 mother-child pairs in mothers who were hypothyroid during pregnancy and analyzed whether first trimester perchlorate levels in the highest 10% of the study population were associated with an increased risk of a low IQ in the offspring. (1)

The study reported that perchlorate was detectable in 100% of women and median iodine levels were low (72µg/L in urine). Maternal perchlorate levels in the highest 10% of the population were associated with a 214% increased risk of a lowered IQ in the children. Furthermore, the highest perchlorate-exposed children had a greater negative impact on verbal IQ. Maternal thyroid hormone supplementation did not reduced the negative impact of perchlorate on the children’s IQ.

Folks, this is an incredibly important article. Our perchlorate (and other toxic halides such as bromine and fluoride) exposure continues to increase at the same time iodine levels have fallen over 50% during the last 40 years. It should be of no surprise to anyone that our children’s health and mental status has suffered greatly during the last few decades.

What can you do? Unfortunately, our exposure to perchlorate and other toxic halides is not going to decrease. However, there is a simple and easy solution—ensure that women of child-bearing age ingest adequate amounts of iodine in order to maintain optimal thyroid function.  Furthermore, it is important to ensure that young women eat a healthy diet free of toxic halides.  Perchlorate will cause more problems when iodine levels are low. Also, drink filtered water that is free of perchlorate. You cannot be sure that tap water is free of perchlorate. Therefore, it is important to filter your tap water. A good reverse osmosis or distillation system will remove perchlorate from the water supply. To find out more about home water systems, contact Tom Lee at United Standard: 248.557.7379. More information about perchlorate and other toxic halides can be found in my book, Iodine: Why You Need It, Why You Can’t Live Without It, 5th Edition.

1. J. of Clin. Endocrin. and Metab. 2014. Doi: 10.1210/jc.2014-1901)

Author Info

David Brownstein