By Ern Banawa

Fatigue, depression, hair loss, and restlessness. These are just some of the symptoms of hypothyroidism, a disorder that makes the thyroid gland produce insufficient hormones. For women who have to contend with these uncomfortable symptoms, it seems they have to hurdle again another complication: babies born to mothers with untreated hypothyroidism have lower IQ.

In the new study by New England Journal of Medicine (NEJM), it reports that untreated hypothyroidism during pregnancy may affect a child's psychological development, and result in substantially lower I.Q. levels, reduced motor skills, and problems with attention, language and reading.

Disease as factor for lower I.Q.

There is approximately 1 out of every 50 women who have hypothyroidism during pregnancy. However, other experts believe this number may actually be far larger, and that a larger percentage of the population is undiagnosed and undertreated.

The research discovered that women with untreated underactive thyroids during pregnancy are nearly four times more likely to have children with lower I.Q. scores.

‘Hypothyroidism in pregnant women can adversely affect their child's subsequent performance on neuropsychological tests, wrote researchers from the Foundation for Blood Research in Scarborough, Maine.

The research team, led by Dr. James Haddow, vice president and medical director for the Foundation for Blood Research, looked at the IQ scores of 7- to 9-year old children born to 124 healthy women, and children in the same age range born to 62 women with hypothyroidism. The children took part in 15 psychological tests of intelligence, attention, language, reading and school problems, and visual-motor performance.

The study showed that 19 percent of the children born to mothers with thyroid deficiency had IQ scores of 85 or lower. This was compared to a reduced IQ level of only 5 percent of those born to mothers without such thyroid problems. According to Haddow, the range below 85 I.Q. level can mean significant impairment for children.

The children whose scores are in this range may face life-long developmental challenges. It might be possible to prevent these problems through the early diagnosis and treatment of thyroid disease in their mothers.

Proof that researchers stumbled on a discovery, the children of the mothers who were treated for hypothyroidism scored similarly to the children of healthy mothers.

Early checking for problems

"These findings suggest that early detection and treatment for hypothyroidism of the mother during pregnancy might be an important factor in the intelligence and well-being of her child," said Haddow. "However, these data do not allow us to determine whether detection and treatment must be accomplished prior to the pregnancy to be effective, or whether they will be effective if done early in pregnancy."

In 95% of cases, hypothyroidism is due to a problem in the thyroid gland itself, where the gland simply produces inadequate amounts of thyroid hormones. One of the causes of hypothyroidism includes complications of either thyroid surgery or radio-iodine ablation treatments for hyperthyroidism (abnormally high levels of thyroid hormones); an autoimmune disorder, where the body's own immune system attacks the thyroid; or an inborn (congenital) thyroid defect. The other 5% of cases, the cause lies in the hypothalamus or pituitary gland rather than in the thyroid gland itself.

Currently, about 1% of American adults suffer from some form of hypothyroidism, although the problem is more common in the elderly. About 1 in every 5000 babies is born with congenital hypothyroidism.