Iodine Intake and Thyroid Function in Pregnant Women in a Private Clinical Practice in Northwestern Sydney before Mandatory Fortification of Bread with Iodised Salt

Aim. The primary objective of the study was to assess the iodine nutritional status, and its effect on thyroid function, of pregnant women in a private obstetrical practice in Sydney.Methods. It was a cross-sectional study undertaken between November 2007 and March 2009. Blood samples were taken from 367 women at their first antenatal visit between 7 and 11 weeks gestation for measurement of thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels and spot urine samples for urinary iodine excretion were taken at the same time as blood collection.Results. The median urinary iodine concentration (UIC) for all women was 81 μg/l (interquartile range 41–169 μg/l). 71.9% of the women exhibited a UIC of <150 μg/l. 26% of the women had a UIC <50 μg/l, and 12% had a UIC <20 μg/l. The only detectable influences on UIC were daily milk intake and pregnancy supplements. There was no statistically significant association between UIC and thyroid function and no evidence for an effect of iodine intake on thyroid function.Conclusions. There is a high prevalence of mild to moderate iodine deficiency in women in Western Sydney but no evidence for a significant adverse effect on thyroid function. The 6.5% prevalence of subclinical hypothyroidism is unlikely to be due to iodine deficiency.

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Urinary iodine excretion in urine samples among children in Dang district, Gujarat

International Journal of Community Medicine and Public Health ◽

10.18203/2394-6040.ijcmph20172820 ◽

2017 ◽

Vol 4 (7) ◽

pp. 2339

Author(s):

Rahul Damor ◽

Jatin Chhaya ◽

Sukesha Gamit ◽

Jayant Patel ◽

J. K. Kosambiya

Keyword(s):

Iodine Deficiency ◽

Primary Schools ◽

Urinary Iodine ◽

Human Growth ◽

Iodine Intake ◽

Urine Samples ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Cross Sectional ◽

Iodine Excretion

Background: Iodine is an essential micronutrient required for normal human growth and development as it is needed for the synthesis of thyroid hormones produced by thyroid glands. The sicknesses occurred due to deficiencies of iodine in the nutrition are termed iodine deficiency disorders. Urinary iodine concentration is the prime indicator of a person’s nutritional iodine status. So, the aim of this study was to assess the status of iodine deficiency based on median urinary iodine excretion.Methods: Community based cross sectional study was carried out among purposively selected primary schools of the Dang district. All students between the age group of 6 to 12 years who were present on the day of visit were included in the study. A total 387 urine samples were collected during the period of August 2015 to September 2016.Results: Based on median urinary iodine excretion, among total analysed samples, about 6.5% samples confirmed severe iodine deficiency, 22% samples showed moderate iodine deficiency and about 36% samples indicated mild iodine deficiency. About one third (31.3%) samples suggested optimum iodine intake. Only few samples (4.4%) revealed more than required iodine intake.Conclusions: About one third (31.3%) of the surveyed population had adequate iodine intake while majority (64.4%) of them had inadequate iodine intake.

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High prevalence of iodine deficiency in pregnant women living in adequate iodine area

Endocrine Connections ◽

10.1530/ec-18-0131 ◽

2018 ◽

Vol 7 (5) ◽

pp. 762-767 ◽

Cited By ~ 9

Author(s):

Verônica Carneiro Borges Mioto ◽

Ana Carolina de Castro Nassif Gomes Monteiro ◽

Rosalinda Yossie Asato de Camargo ◽

Andréia Rodrigues Borel ◽

Regina Maria Catarino ◽

...

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Thyroid Volume ◽

Adverse Outcomes ◽

Urinary Iodine Concentration ◽

Serum Thyroglobulin ◽

Cross Sectional ◽

Iodine Status

Objectives Iodine deficiency during pregnancy is associated with obstetric and neonatal adverse outcomes. Serum thyroglobulin (sTg) and thyroid volume (TV) are optional tools to urinary iodine concentration (UIC) for defining iodine status. This cross-sectional study aims to evaluate the iodine status of pregnant women living in iodine-adequate area by spot UIC and correlation with sTg, TV and thyroid function. Methods Two hundred and seventy-three pregnant women were evaluated at three trimesters. All had no previous thyroid disease, no iodine supplementation and negative thyroperoxidase and thyroglobulin antibodies. Thyroid function and sTg were measured using electrochemiluminescence immunoassays. TV was determined by ultrasonography; UIC was determined using a modified Sandell–Kolthoff method. Results Median UIC was 146 µg/L, being 52% iodine deficient and only 4% excessive. TSH values were 1.50 ± 0.92, 1.50 ± 0.92 and 1.91 ± 0.96 mIU/L, respectively, in each trimester (P = 0.001). sTg did not change significantly during trimesters with median 11.2 ng/mL and only 3.3% had above 40 ng/mL. Mean TV was 9.3 ± 3.4 mL, which positively correlated with body mass index, but not with sTg. Only 4.5% presented with goitre. When pregnant women were categorized as iodine deficient (UIC < 150 µg/L), adequate (≥150 and <250 µg/L) and excessive (≥250 µg/L), sTg, thyroid hormones and TV at each trimester showed no statistical differences. Conclusions Iodine deficiency was detected frequently in pregnant women living in iodine-adequate area. sTg concentration and TV did not correlate to UIC. Our observation also demonstrated that the Brazilian salt-iodization programme prevents deficiency, but does not maintain iodine status within adequate and recommended ranges for pregnant women.

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Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey

British Journal Of Nutrition ◽

10.1017/s0007114512004473 ◽

2012 ◽

Vol 109 (12) ◽

pp. 2276-2284 ◽

Cited By ~ 32

Author(s):

Stefanie Vandevijvere ◽

Sihame Amsalkhir ◽

Ahmed Bensouda Mourri ◽

Herman Van Oyen ◽

Rodrigo Moreno-Reyes

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Childbearing Age ◽

Third Trimester ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Iodine Status

Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n1311) was 124·1 μg/l and 122·6 μg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118·3 μg/l) was significantly lower than that in the third trimester (131·0 μg/l) but significantly higher than among non-pregnant women (84·8 μg/l). Iodine-containing supplement intake was reported by 60·8 % of the women and 57·4 % of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 μg iodine as recommended.

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A cross-sectional study on iodine status among pregnant and non-pregnant women of Tripura: a North-Eastern state of India

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20190359 ◽

2019 ◽

Vol 7 (2) ◽

pp. 486

Author(s):

Nilratan Majumder ◽

Balaram Sutradhar ◽

Saradindu Riang ◽

Shib Sekhar Datta

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Cross Sectional Study ◽

Iodine Intake ◽

Urinary Iodine Excretion ◽

Metabolic Demand ◽

Cross Sectional ◽

Iodine Status ◽

Iodine Excretion

Background: Due to excess metabolic demand of iodine in pregnancy, pregnant women and lactating mother and their neonates are most vulnerable of iodine deficiency disorder. Urinary iodine excretion is a good marker of recent dietary iodine intake. Thus, present study was conducted to assess the iodine status and median urinary iodine excretion (UIE μg/lit) among pregnant and non-pregnant women of Tripura.Methods: Tribal and Bengali pregnant and non-pregnant women from Bokafa and Jolaibari Block of South Tripura district were included in the study. Urinary iodine excretion was done using simple micro plate method. Salt iodine was estimated using iodometric titration. All the tests were performed at CNRT Lab, ICMR, India.Results: Total number of subjects included in this study was 1071. Total number of urine samples collected from pregnant and non-pregnant women was 538 and 533 respectively. Median value of UIE in pregnant and non-pregnant women of Tripura was 155.0µg/L and 130.0µg/L. In pregnant women percentage prevalence of severe (<20µg/L), moderate (20-49µg/L) and mild iodine deficiency (50-149µg/L) was found in 4.1%, 15.1% and 29.6% subjects. In case of non-pregnant women severe (<20µg/L), moderate (20-49µg/L) and mild iodine deficiency (50-99µg/L) was found in 0.6%, 9.6%, 27.8% subjects respectively. The overall prevalence of iodine deficiency was found in 48.8% pregnant women, compared to 38.0% non-pregnant subjects.Conclusions: Efforts towards universal salt iodization need to be stepped-up in Sub-Himalayan region (NE part of India) and pregnant and lactating mothers may be targeted with alternate iodine supplements (Colloidal Iodine).

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Iodine Deficiency in Latvia: Current Status and Need for National Recommendations

Proceedings of the Latvian Academy of Sciences Section B Natural Exact and Applied Sciences ◽

10.1515/prolas-2017-0071 ◽

2017 ◽

Vol 71 (6) ◽

pp. 401-407

Author(s):

Ilze Konrāde ◽

Ieva Kalere ◽

Ieva Strēle ◽

Marina Makrecka-Kūka ◽

Vija Veisa ◽

...

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Medical Decision ◽

Current Status ◽

Urinary Iodine Concentration ◽

Childbearing Age ◽

Cross Sectional

Abstract In the absence of a mandatory salt iodisation programme, two nationwide cross-sectional cluster surveys revealed persisting iodine deficiency among Latvian schoolchildren during the spring season and a noteworthy iodine deficiency in pregnant women in Latvia; these deficiencies warrant intervention. The consequences of mild-to-moderate iodine deficiency during pregnancy and lactation can adversely affect foetal brain development. Data from a Latvian population survey revealed the consumption of approximately 100 μg of iodine per day through foods and iodised salt. Therefore, strategies to increase the consumption of iodine-containing products should be implemented, particularly for children. In addition, to meet the increased iodine requirement during pregnancy, pregnant women should take daily supplements containing 150 μg iodine from the earliest time possible. All women of childbearing age should be advised to increase their dietary iodine intake by using iodised table salt and iodine-rich products: seafood, milk and milk products. For women with pre-existing thyroid pathologies, the medical decision should be considered on a case-by-case basis. Urinary iodine concentration monitoring among schoolchildren and pregnant women and neonatal thyrotropin registry analysis every five years would be an appropriate strategy for maintaining iodine intake within the interval that prevents iodine deficiency disorders.

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Adequately iodized salt is an important strategy to prevent iodine insufficiency in pregnant women living in Central Java, Indonesia

PLoS ONE ◽

10.1371/journal.pone.0242575 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0242575

Author(s):

Ina Kusrini ◽

Jessica Farebrother ◽

Donny Kristanto Mulyantoro

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Interquartile Range ◽

Iodized Salt ◽

Vulnerable Groups ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration

Iodine is an essential micronutrient for cognitive development and growth. Optimal intakes are critical during pregnancy. We report the iodine status and thyroid function of pregnant women living in areas previously affected by severe iodine deficiency and in longstanding iodine sufficient areas in Java, Indonesia. This cross-sectional study was conducted in Magelang, Java, from July to November 2015, in four sub-districts; two previously affected by severe iodine deficiency (area 1) and two that were iodine-sufficient (area 2). Iodine intake was estimated using median urinary iodine concentration in spot samples and mean urinary iodine excretion in 3 x 24-hour samples, thyroid hormones (thyroid-stimulating hormone and free thyroxine) were measured in venous blood samples, and iodine content of household salt samples was estimated by titration. We recruited a total of 244 pregnant women, 123 in area 1 and 121 in area 2. Urinary iodine results suggested adequate habitual iodine intakes in both areas (median urinary iodine concentration in area 1: 222 μg/l (interquartile range 189, 276 μg/l), area 2: 264 μg/l (interquartile range 172, 284 μg/l), however, the risk of inadequate intakes increased with advancing trimester (Odds Ratio = 2.59 (95% CI 1.19–5.67) and 3.85 (95% CI 1.64–9.02) at second and third trimesters, respectively). Estimated prevalence of thyroid function disorders was generally low. Salt was iodized to approximately 40 ppm and foods rich in native iodine did not contribute significantly to dietary intakes. Adequately iodized salt continues to prevent iodine insufficiency in pregnant women living in areas previously affected by severe iodine deficiency in Java, Indonesia. Monitoring and surveillance, particularly in vulnerable groups, should be emphasized to ensure iodine sufficiency prevails.

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Evaluation of median urinary iodine concentration cut-off for defining iodine deficiency in pregnant women after a long term USI in China

Nutrition & Metabolism ◽

10.1186/s12986-019-0381-4 ◽

2019 ◽

Vol 16 (1) ◽

Cited By ~ 4

Author(s):

Huidi Zhang ◽

Meng Wu ◽

Lichen Yang ◽

Jinghuan Wu ◽

Yichun Hu ◽

...

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Normal Thyroid ◽

Normal Thyroid Function

Abstract Background The WHO/UNICEF/ICCIDD define iodine deficiency during pregnancy as median urinary iodine concentration (MUIC) ≤ 150 μg/L. China implemented universal salt iodization (USI) in 1995, and recent surveillance showed nationwide elimination of iodine deficiency disorders (IDD). Data from 2014 showed that the MUIC in 19,500 pregnant women was 154.6 μg/L and 145 μg/L in 9000 pregnant women in 2015. However, symptoms of iodine deficiency were absent. Our study sought to evaluate whether MUIC below 150 μg/L affects thyroid function of Chinese pregnant women and their newborns in Chinese context. Methods We screened 103 women with normal thyroid function and MUIC lower than 150 μg/L during week 6 of pregnancy at Peking Union Medical College Hospital. Patient demographics and dietary salt intake were recorded. Subjects were followed at 12, 24, and 32 gestational weeks. At each visit, a 3-day dietary record, drinking water samples, and edible salt samples were collected and analyzed for total dietary iodine intake. Additionally, 24-h urine iodine and creatinine were measured. Blood tests assessed thyroid function in both mothers and newborns. Results Of 103 pregnant women enrolled, 79 completed all follow-up visits. Most subjects maintained normal thyroid function throughout pregnancy. However, 19 had thyroid dysfunction based on thyroid stimulating hormone and free thyroxine levels. The median serum iodine was 71 μg/L (95% CI: 44, 109). The median thyroglobulin was < 13 μg/L. values above this level indicate iodine deficiency in pregnant women. The median dietary iodine intake during pregnancy, derived from the 3-day record and measures of water and salt, was 231.17 μg/d. Assuming 90% urinary iodine excretion (UIE), 200.11 μg/d UIE means the 222.34 μg iodine loss per day, suggesting that subjects had a positive iodine balance throughout pregnancy. All neonatal blood samples showed TSH levels lower than 10 mIU/L, indicating normal thyroid function. No significant difference was found among gestational weeks for urinary iodine, and the MUIC in subjects who completed 3 follow-up visits was 107.41 μg/L. Conclusion Twenty years after implementing USI, expectant Chinese mothers with MUIC of 107.4 μg/L, less than the WHO’s 150 μg/L benchmark, maintained thyroid function in both themselves and their newborn babies.

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Iodine deficiency during pregnancy: a national cross-sectional survey in Latvia

Public Health Nutrition ◽

10.1017/s1368980015000464 ◽

2015 ◽

Vol 18 (16) ◽

pp. 2990-2997 ◽

Cited By ~ 7

Author(s):

Ilze Konrade ◽

Ieva Kalere ◽

Ieva Strele ◽

Marina Makrecka-Kuka ◽

Anna Jekabsone ◽

...

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Dietary Habits ◽

Urinary Iodine ◽

Fetal Brain ◽

Iodine Intake ◽

Antibody Concentration ◽

Urinary Iodine Concentration ◽

Cross Sectional Survey ◽

Cross Sectional

AbstractObjectiveLow iodine intake during pregnancy may cause thyroid dysfunction, which results in inadequate fetal brain development. In the absence of a universal salt iodization programme, we conducted a nationwide survey of iodine deficiency in pregnant women in Latvia.DesignA countrywide twenty-cluster survey, with at least twenty women per cluster. Participants completed a questionnaire on dietary habits concerning iodine intake (n 739). Thyroid function (thyroid-stimulating hormone, free thyroxine and thyroperoxidase antibodies) was measured (n 550). Urinary iodine was measured using the ammonium persulfate method (n 696).SettingThe survey was performed in all regions of Latvia during the spring and autumn seasons in 2013.SubjectsPregnant women (n 829).ResultsThe median creatinine (Cr)-standardized urinary iodine concentration (UIC) was 80·8 (interquartile range (IQR) 46·1–130·6) µg/g Cr or 69·4 (IQR 53·9–92·6) µg/l during pregnancy, and 81 % of pregnant women had UIC levels below the WHO recommended range of 150–250 µg/g Cr. The UIC was lowest during the first trimester of pregnancy, 56·0 (IQR 36·4–100·6) µg/g Cr, reaching higher concentrations of 87·5 (IQR 46·4–141·7) µg/g Cr and 86·9 (IQR 53·8–140·6) µg/g Cr in the second and third trimesters, respectively. Women taking supplements containing ≥150 µg iodine (6·8 % of respondents) had non-significantly higher UIC than did women without supplementation (96·2 v. 80·3 µg/g Cr, respectively, P=NS). Thyroperoxidase antibody concentration did not correlate significantly with UIC: Spearman’s ρ=−0·012, P=0·78.ConclusionsThe median UIC indicates iodine deficiency in pregnant women in Latvia. Iodine supplementation (150 µg daily) and regular UIC monitoring should be suggested to overcome iodine deficiency and to reach the recommended levels without inducing autoimmune processes.

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Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2016-2829 ◽

2016 ◽

Vol 102 (1) ◽

pp. 23-32 ◽

Cited By ~ 30

Author(s):

Sara Stinca ◽

Maria Andersson ◽

Sandra Weibel ◽

Isabelle Herter-Aeberli ◽

Ralph Fingerhut ◽

...

Keyword(s):

Pregnant Women ◽

Reference Range ◽

Urinary Iodine ◽

Iodine Intake ◽

Dried Blood Spot ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Cross Sectional ◽

Iodine Status ◽

Blood Spot

Abstract Context: Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies. Objectives: Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status. Design, Setting, and Participants: Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake. Main Outcome Measures: We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb. Results: In the reference population, the median DBS-Tg was 9.2 μg/L (95% confidence interval, 8.7 to 9.8 μg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 μg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative. Conclusions: A median DBS-Tg of ∼10 μg/L with <3% of values ≥44 μg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.

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Development and validation of an iodine-specific FFQ to estimate iodine intake in Australian pregnant women

British Journal Of Nutrition ◽

10.1017/s0007114515000197 ◽

2015 ◽

Vol 113 (6) ◽

pp. 944-952 ◽

Cited By ~ 14

Author(s):

Dominique Condo ◽

Maria Makrides ◽

Sheila Skeaff ◽

Shao J. Zhou

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Optimal Growth ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Food Record ◽

Total Iodine ◽

Supplement Use

Adequate iodine is important during pregnancy to ensure optimal growth and development of the offspring. We validated an iodine-specific FFQ (I-FFQ) for use in Australian pregnant women. A forty-four-item I-FFQ was developed to assess iodine intake from food and was administered to 122 pregnant women at 28 weeks gestation. Iodine supplement use was captured separately at 28 weeks gestation. Correlation between iodine intake from food estimated using the I-FFQ and a 4 d weighed food record as well as correlation between total iodine intake and 24 h urinary iodine excretion (UIE), 24 h urinary iodine concentration (UIC), spot UIC and thyroid function were assessed at 28 weeks gestation. A moderate correlation between the two dietary methods was shown (r0·349,P< 0·001), and it was strengthened with the addition of iodine supplements (r0·876,P< 0·001). There was a fair agreement (k= 0·28,P< 0·001) between the two dietary measures in the classification of women as receiving adequate ( ≥ 160 μg/d) or inadequate ( < 160 μg/d) iodine intake from food, but the limits of agreement from the Bland–Altman plot were large. Total iodine intake was associated with 24 h UIE (β = 0·488,P< 0·001) but not with spot UIC. Iodine intake from food using the I-FFQ was assessed at study entry ( < 20 weeks gestation) in addition to 28 weeks gestation, and there was a strong correlation in iodine intake at the two time points (r0·622,P< 0·001), which indicated good reproducibility. In conclusion, the I-FFQ provides a valid tool for estimating iodine intake in pregnant women and can be used to screen women who are at risk of inadequate intake.

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