Iodine Deficiency While Pregnant Can Hurt Baby's IQ Study reminds women to eat fish, drink milk By Evann Gastaldo, Newser Staff Posted May 22, 2013 2:24 PM CDT 10 comments Comments (Shutterstock) (Newser) – Don't forget to include dairy products and fish in your diet while pregnant: Those are good sources of iodine, and a new study finds that it's important for your baby's mental development that you get enough of it while you're expecting. Researchers looked at more than 1,000 pregnant women who had been tested during a long-term health survey, and found that the children of women who had been iodine-deficient were much more likely to have a lower verbal IQ score as well as lower reading scores at ages 8 and 9. "We saw a three-point IQ difference between children who were born to mothers with low iodine in early pregnancy and children who were born to mothers above the cut-off," a researcher tells the BBC. And the more deficient the mother had been, the lower the children's scores were, the Guardian reports. Iodine is a critical part of thyroid function, helping to produce the hormones that impact fetal brain development. Other studies have found iodine deficiency to be harmful to the brain, Bloomberg reports, but few have looked at the effect in pregnant women.