Hypothyroidism equals lower IQ

Intelligence is at a premium in our achievement-oriented society these days. Today, it is well established that intelligence is determined by heredity, though the extent of genetic influence is still debatable. However, it is also accepted that environmental factors can enhance a child's inherent intelligence. As a result, parents are constantly striving to find new ways to improve their children's intellect. Parents would be interested to know that based on the results of a new study, they can now take protective measures regarding their baby's intelligence even before the baby is born. 

Researchers have found evidence to show that an underactive thyroid gland (a condition known as hypothyroidism) in a pregnant woman can lower a baby's IQ by as much as seven points. To quote researchers from the Foundation for Blood Research in Scarborough, Maine, "Hypothyroidism in pregnant women can adversely affect their child's subsequent performance on neuropsychological tests."

The thyroid is a twin-lobed gland located just below the voice box, which secretes hormones that control metabolism, growth and development. Low thyroid or hypothyroidism is characterized by symptoms such as fatigue, weight gain, dry skin, and sometimes constipation and heavy periods. Researchers have found that the IQ was affected even when the pregnant woman's hypothyroidism was mild and no symptoms were manifested. 
 

Dr. James Haddow's findings

In a study published by the 'New England Journal of Medicine', a team led by Dr. James Haddow compared the intelligence scores of seven to nine-year old children born to 124 normal women, and children within the same age group born to 62 women with hypothyroidism. 

The findings of this study showed that the average IQ score for a child born to a mother with a thyroid deficiency was four points lower than for a child of a woman without a thyroid problem. Among the children of 48 of the thyroid-deficient women, the average IQ score was seven points lower. 19% of these children had IQ scores of 85 or lower, compared with just 5% of the children whose mothers had normal thyroid glands during pregnancy. (The average score on an IQ test is 100). 

Dr. James Haddow and his team have come to the conclusion that "systematic screening for hypothyroidism early in pregnancy may be worthwhile, even when the degree of deficiency is mild and does not cause immediate clinical manifestations in the woman."
 

Precautionary measures

However, Dr. Robert Utiger, the deputy editor of the 'New England Journal of Medicine', has written in an editorial that before making it compulsory for pregnant women to be screened for hypothyroidism, a campaign should be undertaken to deal with the problem at its root. Iodine is essential for the production of thyroid hormones. Therefore, Dr. Utiger recommends that iodine should be added to prenatal vitamins and increased amounts of iodine should be added to salt and other foods. The beneficiaries of such a campaign would not just be pregnant women and their children, but everybody in general.