With all the things to keep in mind while pregnant, you may not have considered your iodine intake. But research suggests perhaps you should: a study published in the Journal of Nutrition found a correlation between less than adequate maternal dietary iodine intake and an increased risk of childhood development delays. For the study, researchers recruited 48,297 pregnant women. At mid-pregnancy, the women answered questionnaires about their diets and supplement use since becoming pregnant. Researchers used this data to estimate the women’s iodine intake from supplements and foods. Three years later, researchers asked the mothers to complete a standardised report on their children’s language, motor skills, and any behaviour problems. Looking at all of the data collected, they found that:

• Average iodine intake from food alone was 122 micrograms per day, well below the recommended daily allowance of 220 micrograms per day during pregnancy.
• Iodine intake from food was closely correlated with the consumption of specific foods known to be iodine sources: milk, yoghurt, fish, and eggs.
• Among women whose only source of iodine was food, low iodine intake during pregnancy was associated with language delays, poor fine motor skills, and more behaviour problems in their children.
• The researchers calculated that approximately 5% of cases of language delays and 16% of cases of behaviour problems were related to maternal dietary iodine intake of less than 160 micrograms per day.
• When all of the mother-child pairs were included in the analysis—those who took supplements with iodine as well as those who did not—iodine from supplements was not associated with a protective effect.

It is important to bear in mind that these findings are observational: although the researchers adjusted their statistical analysis to consider other factors that could influence neurological development, such as maternal age and intake of nutrients like folic acid and omega-3 fatty acids, it is still possible that some other factor was responsible for the association observed between intake of iodine from foods and childhood neurological development. Nonetheless, iodine is known to be important for foetal health, so getting enough during pregnancy is important.

How do you get enough iodine in your diet? Eating the foods identified in this study as iodine sources—milk, yoghurt, eggs, and seafood—is a good way to ensure adequate intake. But remember to limit fish consumption to reduce the risk of harm from ocean contaminants. The US Food and Drug Administration provides useful information to help you make good choices about which fish and how much to eat. As always, the best approach is to eat a balanced diet and talk with your doctor about any nutritional worries or other concerns you have. Then you can get back to pondering the fun stuff, like what colour to paint the nursery.

Source: Journal of Nutrition