12 January - 20 June 2016

Iodine in pregnancy and cognitive outcome in offspring

5 June 13

A study published in the Lancet by scientists from the University of Surrey and the University of Bristol has investigated the effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children.  The World Health Organisation recommends that pregnant women eat iodine rich foods, as iodine plays a part in the healthy developments of a baby’s brain and nervous system.  They recommend that pregnant and breastfeeding women consume 250 µg a day. Changes to dairy farming in the 1930s meant that there was an increased amount of iodine in milk in the UK.  As there is a reduction in incidence of goitre, a thyroid problem, it is thought that levels of iodine in the UK are therefore sufficient.  Previous studies have however indicated that adolescent schoolgirls and pregnant women may have mild iodine deficiency. Bath et al analysed data from 1040 women involved in the Avon Longitudinal Study of Parents and Children, a cohort study which investigates the health outcome of children born during the 1990s.  The scientists measured urinary iodine concentration (and creatinine to correct for urine volume) in stored samples from first-trimester pregnant women. The participants were chosen on the basis of a singleton pregnancy and availability of both a urine sample from the first trimester and also being able to measure their child’s IQ at 8 years old.   IQ was assessed using a validated scale.  At nine years of age Bath et al assessed the children’s reading speed, accuracy and comprehension.  They then investigated, after taking into a number of confounding factors (including breastfeeding history, and dietary factors such as intake of omega 3 and iron), the association with iodine pregnancy status and a child’s IQ at eight and reading ability at nine. Two thirds of the participants were found to be deficient in iodine during pregnancy, with those being deficient being younger, less educated but having less exposure to stress during pregnancy. Bath et al found that compared with those who had adequate iodine levels, the children of women with iodine deficiency were at significantly higher risk of having a  verbal IQ score and/or a reading accuracy score and/or a reading comprehension in the lowest quartile. No association however was found for overall IQ or performance IQ and iodine deficiency.   In conclusion Bath et al state that their results ”emphasise the risk that iodine deficiency can pose to the developing infant, even in a country classified as only mildly iodine deficient.”

RSSL's Metals Team can determine iodine by ICP-MS down to a detection limit of 0.05 ppm. For more information please contact Customer Services on Freephone 0800 243482 or email enquiries@rssl.com.

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry