Iodine intake in pregnancy in Ireland — A cause for concern?
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Adequate dietary iodine intake is necessary to maintain maternal thyroid function at a level permitting normal neuropsychological development of the foetus.
Aims and Methods
To determine dietary iodine status by measuring urinary iodine excretion (UIE), proportional to dietary intake, in Irish mothers during the first trimester of pregnancy.
Median UIE showed seasonal variations, being lower in summer than in winter. The median values in pregnant women were, summer 45μg/l, winter 68μg/l. Equivalent values for controls were 43 and 91μg/l respectively UIE required to achieve WHO recommended daily iodine intakes would be 120–180μg/l. In the Irish subjects UIE values suggestive of iodine deficiency (<50μg/l) were observed in 55% of pregnant women tested in summer and 23% in winter. Dairy milk iodine, a major dietary iodine source, showed similar variation.
While there is as yet no available evidence of widespread thyroid hypofunction in the Irish obstetric population, the findings are a cause of concern, which if confirmed by a more comprehensive investigation, may indicate the need for iodine prophylaxis.
- Glinoer D. The regulation of thyroid function in pregnancy: pathways of endocrine adaptation from physiology to pathology.Endocr Rev 1997;18: 404–433. CrossRef
- Delange F. Iodine deficiency as a cause of brain damage. Postgraduate Medical Journal 2001;77: 217–220. CrossRef
- WHO, 2001. NHD01/1. Assessment of Iodine Deficiency Disorders and Monitoring their Elimination. Geneva.
- WHo, 2004. Iodine status worldwide. WHO Global Database on iodine deficiency. (http://whqlibdoc.who. int/publications/2004/9241592001.pdf) Geneva.
- Haddow JE, Palomaki GE, Allan WC et al. Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child.New Engl J Med 1999;341: 549–555. CrossRef
- Morreale De Escobar G, Obregon MJ, Escobar Del Ray. Is neuropsychological development related to maternal hypothyroidism or to maternal hypothyroxinemia?J Clin Endocrinol Metab. 2000;85(11): 3975–3987. CrossRef
- Boyages SC, Collins JK, Maberly GF, Jupp JJ, Morris J, Eastman CJ. Iodine deficiency impairs intellectual and neuromotor development in apparently-normal persons. A study of rural inhabitants of north-central China.Med J Aust. 1989;150(12): 676–82.
- Santiago-Fernandez P, Torres-Barahona R, Muela-Martinez JA et al. Intelligence quotient and iodine intake: a cross-sectional study in children.J Clin Endocrinol Metab. 2004;89(8)3851–7. CrossRef
- Salarkia N, Mirmiran P, Azizi F. Timing of the effect of iodine supplementation on intelligence quotients of schoolchildren.Int J Endocrinol Metab 2004;2: 95–102.
- Vermiglio F, Lo Presti VP, Moleti M et al. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: A possible novel iodine deficiency disorder in developed countriesJ Clin Endocrinol Metab 2004;89: 6054–6060. CrossRef
- Aboul-Khair SA, Turnbull AC, Hytten FE. The physiological changes in thyroid function during pregnancy.Clin. Sci. 1964;27: 195–207.
- Smyth PPA, Smith DF, Radcliff M, O’Herlihy C. Maternal iodine status and thyroid volume during pregnancy: correlation with neonatal intake.J. Clin. Endocrinol. Metab. 1997;82: 2840–2843. CrossRef
- Brander L, Als C, Buess H, Haldimann F, Harder M, Hanggi W. Urinary iodine concentration during pregnancy in an area of unstable dietary iodine intake in Switzerland.J. Endocrinol. Invest. 2003;26: 389–396.
- Kung AW, Lao TT, Chau MT, Tam SC, Low LC. Goitrogenesis during pregnancy and neonatal hypothyroxinaemia in a borderline iodine sufficient area.Clin Endocrinol (Oxf). 2000;53: 725–731. CrossRef
- Delange F. Optimal iodine nutrition during pregnancy, lactation and the neonatal period.Int J Endocrinol Metab 2004;2: 95–102.
- Hollowell JG, Staehling NW, Hannon WH et al. Iodine nutrition in the United States. Trends and public health implications: Iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971–1974 and 1988–1994).J Clin Endocr Metab. 1998;83(10): 3401–3408. CrossRef
- Gunton JE, Hams G, Fiegert M, McElduff A. Iodine deficiency in ambulatory participants at a Sydney teaching hospital: is Australia truly iodine replete?Med J. Australia. 1999;171: 467–470.
- Dunn JT. What’s happening to our iodine?J. Clin. Endocrinol. Metab. 1998;83(10): 3398–4000. CrossRef
- Smallridge R, Glinoer D, Hollowell J, Brent G. Thyroid function inside and outside of pregnancy: What do we know and what don’t we know.Thyroid 2005;15: 44–53. CrossRef
- Pearce EN, Pino S, He X, Bazrafshan HR, Lee SL, Braverman LE. Sources of dietary iodine: bread, cows’ milk, and infant formula in the Boston area.J Clin Endocrinol Metab 2004;89: 3421–4. CrossRef
- Ohashi T, Mituso Y, Chandrakant PS, Karmarkar MG, Minoru I. Simple microplate method for determination of Urinary iodine.Clinical Chemistry 2000;46: 4529–536.
- Lauber K. Iodine determination in biological material. Kinetic measurement of the catalytic activity of iodide.Anal Chem. 1975;47(4): 769–71. CrossRef
- O’Donovan DK. The problem of endemic goitre in Ireland. Irish J Med Sci 1950;161–170.
- Smyth PPA, Hetherton AM, O’Carroll D, Smith DF, O’ Halloran J, O’ Donovan DK. Iodine intake in Irelandan update.Irish J Med Sci. 1988;157: 377–379. CrossRef
- Hetherton AM, Smyth PPA, 1993. Status of iodine deficiency in Ireland. IodineDeficiency in Europe — A Continuing Concern. NATO ASI Series, New York, Plenum Press Pg 317–322.
- Smyth PPA. Variation in iodine handling during normal pregnancy.Thyroid 1999;9: 637–642. CrossRef
- Pearce EN, Pino S, He X, Bazrafshan HR, Lee SL, Braverman LE. Dietary iodine in pregnant women from the Boston, Massachussetts area.Thyroid. 2004;14(4): 327–328. CrossRef
- Kibirige MS, Hutchison S, Owen CJ, Delves HT. Prevalence of maternal dietary iodine insufficiency in the north east of England: implications for the foetus. Arch Dis Child Foetal Neonatal Ed. 2004: 89: F436–9. CrossRef
- Zimmerman M, Delange F. Iodine supplementation of pregnant women in Europe: a review and recommendations. Eur J Clin Nutr. 2004;58: 979–984. CrossRef
- Institute of Medicine, Food and Nutrition Board, 2001. In dietary Reference intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium and Zinc. Washington, DC: National Academy Press Pg 258–289.
- Vitti P, Delange F, Pinchera A, Zimmermann M, Dunn JT. Europe is iodine deficient.Lancet. 2003;361: 1226 CrossRef
- Bleichrodt N, Born MP. 1994. A metaanalysis of research on iodine and its relatioship to cognitive development. In Stanbury JB ed The damaged brain of iodine deficiency. New York: Cognizant Communications Corporation Pg 195–200.
- Iodine intake in pregnancy in Ireland — A cause for concern?
Irish Journal of Medical Science
Volume 175, Issue 2 , pp 21-24
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- 1. UCD School of Medicine and Medical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin and National Maternity Hospital, Holles Street, Dublin