Iodine Supplementation During Pregnancy Would Increase Childhood IQs, Reduce Costs Interview with:
Prof. Kate Jolly

Professor of Public Health and Primary Care
Public Health Building
School of Health & Population Sciences
University of Birmingham
Edgbaston Birmingham

Medical Research: What is the background for this study?

Response: The UK is amongst 32 countries worldwide with evidence of iodine deficiency. Severe iodine deficiency during pregnancy is associated with a lower intelligence quotient (IQ) and developmental abnormalities in the children; these are reversible by iodine supplementation during pregnancy. However, the effects of mild or moderate iodine deficiency during pregnancy are less clear as there are no high quality trials of supplementation that have reported the outcome of child IQ. However, in two studies in the UK and Australia, nine year old children of women who had a urinary iodine concentration suggestive of mild iodine deficiency during their pregnancy exhibited reduced educational outcomes and decreased IQ scores compared to children of iodine replete mothers.

Recent research from the UK suggests that the country has become mildly iodine deficient. Many countries address their iodine deficiency by programmes of adding iodine to salt and some recommend that pregnant women take iodine supplements. Neither of these occur in the UK, although some commonly used pregnancy supplements already include iodine.

Controversy about the need for supplementation in pregnancy, the ethics of undertaking a trial in which women would be randomly allocated to have iodine supplements, or not, and the high cost of following-up and assessing large numbers of children makes a trial unlikely.

Medical Research: What are the main findings?

Response: We used an economic model of best available evidence and used assumptions that did not favour iodine supplementation. We found that if all women took iodine supplements for 3 months prior to pregnancy, during their pregnancy and until they ceased breastfeeding, there would be an average increase in each child’s IQ by 1·22 points. This would save the NHS £199 and society £4476 per pregnant woman respectively.

Medical Research: What should clinicians and patients take away from your report?

Response: Current available evidence suggests that a policy of iodine supplementation during pregnancy would be a cost-effective strategy for the UK health service.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: The only way to conclusively find out the benefits of iodine supplementation in pregnancy on children’s development would be to undertake a trial in which half the mothers received iodine supplements and half did not.


Costs and benefits of iodine supplementation for pregnant women in a mildly to moderately iodine-deficient population: a modelling analysis
Published online: August 9, 2015
Mark Monahan, Kristien Boelaert, Kate Jolly, Shiao Chan, Pelham Barton, Tracy E Roberts
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Prof. Kate Jolly (2015). Iodine Supplementation During Pregnancy Would Increase Childhood IQs, Reduce Costs 

Last Updated on August 10, 2015 by Marie Benz MD FAAD