Library Open Repository

The influence of gestational stage on urinary iodine excretion in pregnancy

Downloads

Downloads per month over past year

Stilwell, G and Reynolds, PJ and Parameswaran, V and Blizzard, CL and Greenaway, T and Burgess, JA (2008) The influence of gestational stage on urinary iodine excretion in pregnancy. Journal of Clinical Endocrinology and Metabolism, 93 (5). pp. 1737-1742. ISSN 0021-972X

[img] PDF
Stillwell_J_Clin_Endocrin_Metab.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Introduction: Median urinary iodine concentration (UIC) is the most commonly used indicator of population iodine nutrition. However, its validity as an indicator of dietary intake relies on a stable relationship between dietary iodine intake and urinary excretion. Physiological alterations in normal pregnancy, such as increased glomerular filtration rate, potentially invalidate UIC as an assessment tool in pregnancy. Objective: The objective of the study was to document the impact of advancing gestation on UIC in normal pregnancy and determine whether the current reference intervals for general population iodine monitoring are appropriate for use in the context of pregnancy. Design: Tasmania has a well-described history of mild iodine deficiency (school-age median UIC of 84 µg/liter). We assessed UIC in 759 urine samples from 431 women attending the Antenatal Clinic at the Royal Hobart Hospital, Tasmania’s primary teaching hospital. Main Outcome: The overall median UIC during pregnancy was 75 µg/liter (95% confidence interval 70.03–79.97 µg/liter) at a median gestation of 19.4 wk. Stratification by gestation, however, revealed a dynamic relationship between ioduria and gestation. Median UIC was elevated in early pregnancy and subsequently declined with advancing gestation. Conclusion: In this mildly iodine-deficient population, current reference intervals for UIC overestimated the adequacy of iodine nutrition during the first and early second trimester of pregnancy. Gestation-specific UIC reference intervals are required to classify iodine nutrition during pregnancy. This is particularly important in populations with borderline iodine deficiency.

Item Type: Article
Journal or Publication Title: Journal of Clinical Endocrinology and Metabolism
Page Range: pp. 1737-1742
ISSN: 0021-972X
Identification Number - DOI: 10.1210/jc.2007-1715
Additional Information: Copyright © 2008 by The Endocrine Society
Date Deposited: 16 Mar 2009 07:26
Last Modified: 18 Nov 2014 03:56
URI: http://eprints.utas.edu.au/id/eprint/8490
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page