High Perchlorate Level in Mothers Negatively Affects IQ of Unborn Children

Researchers have found that high levels of common chemical 'perchlorate' can have detrimental effects on the IQ of unborn children.

The study, led by researchers at the Boston University School of Medicine, highlighted the harmful side effects of perchlorate in mother and children. They evaluated data from 487 mother-children pairs, in which the women had underactive thyroid glands. The researchers found that high levels of common and pervasive chemical perchlorate, a compound known to affect the thyroid gland, affects the IQ of the unborn children.

Perchlorate disrupts thyroid gland's ability to produce the hormone, which is needed for normal growth. This naturally-occurring environmental contaminant is found in food and some drinking water supplies. Perchlorate is considered a "likely human carcinogen" by the U.S. Environmental Protection Agency (EPA). It is estimated that nearly 11 million Americans reside in regions where concentrations of perchlorate in public drinking water is significantly higher than what is considered safe.

In the study, conducted in collaboration with researchers at the Cardiff University, the researchers studied the effect of perchlorate on children born to mothers with above average levels of the compound in their system. Out of the total mother-child pairs, 50 women were identified with highest levels of perchlorate in their body and the IQ levels of the children were below average as compared to other children.

"The reason people really care about perchlorate is because it is ubiquitous. It's everywhere," said Elizabeth Pearce, MD, MSc, associate professor of medicine at BUSM. "Prior studies have already shown perchlorate, at low levels, can be found in each and every one of us."

According to the researcher, studies conducted earlier tried to implicate this anti-thyroid activity in pregnant women as a possible cause of hypothyroidism. Hypothyroidism in newborns and children might lead to side effects including below average IQ.

The finding was documented in the Journal of Clinical Endocrinology & Metabolism.