Even Mild Iodine Deficiency in Pregnancy Lowers Child's IQ

Maintaining a sufficient level of iodine during pregnancy is crucial for the mental development of the child. Emphasizing this point, a team of researchers from the U.K. have found that women who had mild or moderate iodine deficiency during pregnancy gave birth to children with low levels of IQ.

Iodine is an important nutrient that helps in the normal development of the brain and nervous system before and after the birth of a child. Since the body cannot produce iodine, it is important to consume foods rich in the nutrient. Cheese, cow's milk, soy milk, yogurt, iodized table salt, shell fish, eggs, seaweed, saltwater fish and soy sauce are some natural sources of dietary iodine.

As it is often difficult to maintain the adequate levels only through diet, health experts state that women planning to get pregnant, already pregnant and breast-feeding should include 150 micrograms (µg) of iron supplements every day.

To analyze the importance of iodine in brain development, professor Margaret Rayman of the University of Surrey and colleagues followed more than 1,000 pregnant women in the U.K. and their children, part of the Bristol-based Avon Longitudinal Study of Parents and Children (ALSPAC).

Iodine levels of the women were measured and recorded at the first trimester. While comparing the results with guidelines by the WHO, the researchers found that a majority of the participants faced iodine deficiency (67 percent).

Later, at age 8 and age 9, children underwent IQ and reading tests. Results showed a clear link between the mother's iodine status in pregnancy and the child's ability to perform. Children of women with iodine deficiency performed worse in verbal IQ, reading accuracy and reading comprehension.

"Our results clearly show the importance of adequate iodine status during early pregnancy, and emphasise the risk that iodine deficiency can pose to the developing infant, even in a country classified as only mildly iodine deficient," Rayman said in a news release.

Concerned with the findings, researchers urge pregnant women to follow a diet rich in iodine.

The study is published in The Lancet.

Supporting the current study, some previous studies have shown that eating fish rich in omega-3 fatty acids during pregnancy benefits the baby's brain development. Researchers found that children's scores in language skills and development went up with the mother's intake of omega-3 fatty acid.