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Mild Iodine Deficiency During Pregnancy Is Associated With Reduced Educational Outcomes in the Offspring: 9-Year Follow-up of the Gestational Iodine Cohort


Hynes, KL and Otahal, P and Hay, I and Burgess, JR, Mild Iodine Deficiency During Pregnancy Is Associated With Reduced Educational Outcomes in the Offspring: 9-Year Follow-up of the Gestational Iodine Cohort, Journal of Clinical Endocrinology and Metabolism, 98, (5) pp. 1954-1962. ISSN 0021-972X (2013) [Refereed Article]


Copyright Statement

Copyright 2013 The Endocrine Society

DOI: doi:10.1210/jc.2012-4249


Context:Severe iodine deficiency (ID) during gestation is associated with neurocognitive sequelae. The long-term impact of mild ID, however, has not been well characterized.Objective:The purpose of this study was to determine whether children born to mothers with urinary iodine concentrations (UICs) <150 g/L during pregnancy have poorer educational outcomes in primary school than peers whose mothers did not have gestational ID (UIC 150 g/L).Design:This was a longitudinal follow-up (at 9 years old) of the Gestational Iodine Cohort. Pregnancy occurred during a period of mild ID in the population, with the children subsequently growing up in an iodine-replete environment.Setting and Participants:Participants were children whose mothers attended The Royal Hobart Hospital (Tasmania) antenatal clinics between 1999 and 2001.Main Outcome Measures:Australian national curriculum and Tasmanian state curriculum educational assessment data for children in year 3 were analyzed.Results:Children whose mothers had UIC <150 g/L had reductions of 10.0% in spelling (-41.1 points, 95% confidence interval [CI], -68.0 to -14.3, P = .003), 7.6% in grammar (-30.9 points, 95% CI, -60.2 to -1.7, P = .038), and 5.7% in English-literacy (-0.33 points, 95% CI, -0.63 to -0.03, P = .034) performance compared with children whose mothers' UICs were 150 g/L. These associations remained significant after adjustment for a range of biological factors (maternal age at birth of child, gestational length at time of birth, gestational age at time of urinary iodine collection, birth weight, and sex). Differences in spelling remained significant after further adjustment for socioeconomic factors (maternal occupation and education).Conclusions:This study provides preliminary evidence that even mild iodine deficiency during pregnancy can have long-term adverse impacts on fetal neurocognition that are not ameliorated by iodine sufficiency during childhood.

Item Details

Item Type:Refereed Article
Keywords:mild iodine deficiency, gestation, literacy, spelling, school age children
Research Division:Health Sciences
Research Group:Epidemiology
Research Field:Epidemiology not elsewhere classified
Objective Division:Health
Objective Group:Specific population health (excl. Indigenous health)
Objective Field:Neonatal and child health
UTAS Author:Hynes, KL (Dr Kristen Hynes)
UTAS Author:Otahal, P (Mr Petr Otahal)
UTAS Author:Hay, I (Professor Ian Hay)
UTAS Author:Burgess, JR (Professor John Burgess)
ID Code:84329
Year Published:2013
Web of Science® Times Cited:210
Deposited By:Menzies Institute for Medical Research
Deposited On:2013-05-07
Last Modified:2017-11-02
Downloads:429 View Download Statistics

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