scholarly journals Mild to moderate iodine deficiency in pregnancy: A matter of debate

2021 ◽  
Vol 5 (1) ◽  
pp. 018-026
Author(s):  
Delshad Hossein ◽  
Azizi Fereidoun
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Urinary Iodine Concentration ◽  
Iodine Nutrition ◽  
Iodine Supplementation ◽  
Iodine Deficiency In Pregnancy ◽  
In Pregnancy

During the last few decades painstaking efforts have been made to eliminate iodine deficiency through the world. Nowadays in regions where dietary iodine intake is adequate or borderline, the main focus is increasing dietary iodine supply in the target population during pregnancy and the first years of life. Severe iodine deficiency during pregnancy increases the risk of irreversible brain damage, intellectual disability, neurologic abnormalities, stunted growth, increased pregnancy loss, infant mortality, impairments in child development and cretinism. The potential effects of mild-to-moderate iodine deficiency are debated. Results from animal studies and observational human studies indicate that maternal mild-to-moderate iodine deficiency disturbs thyroid function in pregnancy and it also may affects fetal neurodevelopment. The effect of supplementation of iodine on thyroid function of pregnant women and their newborn, neurodevelopment of infants and cognitive performance of children have been investigated using iodine nutrition in pregnancy, based on median urinary iodine concentration. However they have found conflicting results regarding the benefits or harms of iodine supplementation in pregnancy. Although many epidemiological, interventional and clinical studies have supported the association between thyroid function in pregnant women and later psychomotor and mental development of their children, the effect of iodine supplementation in pregnant women on neurodevelopment of children is inconclusive. Even in areas with well-established universal salt iodization program, pregnancy could be at risk of having iodine deficiency and despite WHO/ICCIDD/UNICEF recommendation which believe that dietary iodine fortification during pregnancy depends primarily on the extent of pre-existing iodine deprivation, systematic dietary fortification needs to be implemented in this vulnerable group. However, iodine supplementation of mildly iodine deficient pregnant women may not have beneficial effects in their thyroid function or neurodevelopment of their children.

scholarly journals Women Remain at Risk of Iodine Deficiency during Pregnancy: The Importance of Iodine Supplementation before Conception and Throughout Gestation

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 172 ◽  
Author(s):  
Kristen Hynes ◽  
Judy Seal ◽  
Petr Otahal ◽  
Wendy Oddy ◽  
John Burgess
Keyword(s):  
At Risk ◽  
Pregnant Women ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Urinary Iodine Concentration ◽  
Iodine Nutrition ◽  
Supplement Use ◽  
Iodine Supplementation ◽  
The Impact

In Australia, pregnant women are advised to take an iodine supplement (I-supp) (150 µg/day) to reduce risks to the foetus associated with iodine deficiency (ID). To examine the impact of this recommendation on iodine status, and to identify factors that contribute to adequacy during gestation, supplement use and Urinary Iodine Concentration (UIC) was measured in 255 pregnant women (gestation range 6 to 41 weeks) in Tasmania. The median UIC (MUIC) of 133 µg/L (Inter-quartile range 82–233) was indicative of ID, being below the 150–249 µg/L range for adequacy during pregnancy. Women taking an iodine-containing-supplement (I-supp) had a significantly higher MUIC (155 µg/L) (n = 171) compared to the combined MUIC (112.5 µg/L) (n = 84) of those who had never (120 µg/L) (n = 61) or were no longer taking an I-supp (90 µg/L) (n = 23) (p = 0.017). Among women reporting I-supp use, the MUIC of those commencing the recommended 150 µg/day prior to conception was significantly higher than those starting supplementation following pregnancy confirmation: 196 (98–315) µg/L (n = 45) versus 137.5 (82.5–233.5) µg/L (n = 124), p = 0.032. Despite recommendations for iodine supplementation pregnant Tasmanian women remain at risk of ID. Commencing an I-supp of 150 µg/day prior to conception and continuing throughout pregnancy is required to ensure adequacy. Timely advice regarding the importance of adequate iodine nutrition, including supplementation is needed to reduce the risk of irreversible in utero neurocognitive damage to the foetus.

scholarly journals Moderate Iodine Deficiency Is Common in Pregnancy but Does Not Alter Maternal and Neonatal Thyroid Function Tests

2020 ◽  
Vol 11 ◽  
Author(s):  
Tal Schiller ◽  
Arnon Agmon ◽  
Viviana Ostrovsky ◽  
Gabi Shefer ◽  
Hilla Knobler ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Content ◽  
First Trimester ◽  
Thyroid Function Tests ◽  
Neonatal Thyroid Function ◽  
Iodine Deficiency In Pregnancy ◽  
In Pregnancy

IntroductionAn Israeli national survey found that 85% of pregnant women had urinary iodine content (UIC) levels below the adequacy range (<150 µg/L). Widespread desalinated water usage and no national fortification plan are possible causes. Studies assessing relationships between iodine status and maternal and neonatal thyroid function provided varying results. Our aims were to determine whether iodine deficiency was associated with altered maternal or neonatal thyroid function and the factors leading to iodine deficiency.MethodsA cross-sectional study including 100 healthy women without prior thyroid disease, in their first trimester of a singleton pregnancy were recruited from an HMO clinic in central Israel. The women were followed from their first trimester. All women completed a 24-h dietary recall and life habits questionnaires. We tested for UIC, maternal and neonatal thyroid function, maternal autoantibodies, and neonatal outcomes.ResultsMedian UIC in our cohort was 49 µg/L [25%–75% interquartile range (IQR) 16-91.5 µg/L], with 84% below adequacy range. No correlation was found between iodine deficiency and maternal or neonatal thyroid function which remained within normal ranges. Antibody status did not differ, but thyroglobulin levels were significantly higher in iodine insufficient subjects. UIC was higher in women consuming an iodine containing supplement. There was no association between UIC and dietary iodine content or water source.ConclusionsModerate iodine deficiency is common in our healthy pregnant women population. Our data imply that moderate iodine deficiency in pregnancy seem sufficient to maintain normal maternal and neonatal thyroid function.

scholarly journals Indicators of Iodine Status in Pregnancy and Postpartum in a Group of Pregnant Women from Perimarine Area of Romania

2020 ◽  
Vol 26 (2) ◽  
pp. 63-69
Author(s):  
Scrinic Olesea ◽  
Delia Corina Elena ◽  
Toma Geanina Mirela ◽  
Circo Eduard
Keyword(s):  
Pregnant Women ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Iodized Salt ◽  
Urinary Iodine Concentration ◽  
Urinary Creatinine ◽  
Iodine Status ◽  
In Pregnancy

Abstract Objective: Assessment of iodine nutritional status in pregnant women in the perimarine area of Romania, a region without iodine deficiency. Adequate iodine intake is the main source for normal thyroid function, ensuring the need for maternal thyroid hormones during pregnancy, but also for the development and growth of children in the fetal and postpartum period. Material and method: Prospective study performed on 74 pregnant women in the first 2 trimesters of pregnancy, originating from the perimarin area. The following indicators of iodine status were analyzed: urinary iodine concentration (UIC), the ratio between urinary iodine concentration and urinary creatinine (UIC/UCr), the prevalence of maternal goiter and the value of neonatal TSH (thyroid stimulating hormone). Results: The mean gestational age was 11 weeks. The ways of iodine intake are: iodized salt - 59.4%, iodized salt and iodine supplements- 23%, only iodine supplements -10.8% and 6.8% consume only non-iodized salt. The median of UIC was 133.03 mcg/l considered insufficient iodine intake (normal in pregnancy UIC >150 mcg/l), but the adjustment of UIC to urinary creatinine reveals a median of 152.83 mcg/g, a value that reflects an adequate iodine intake. The prevalence of goiter was 25.6% characteristic for a moderate iodine deficiency. The prevalence of neonatal TSH >5 mIU/L was registered in 18.8% characteristic of mild iodine deficiency. Conclusions: Monitoring of the iodine nutritional status is recommended for the prevention of disorders due to iodine deficiency under the conditions of universal salt iodization. Perimarine areas considered sufficient in iodine may show variations in iodine status in subpopulations under certain physiological conditions, such as pregnancy. An indicator of iodine status of the population is UIC, but the UIC/UCr ratio may be a more optimal indicator for pregnant women, to avoid possible overestimated results of iodine deficiency in pregnancy.

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

PLoS ONE ◽  
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.

scholarly journals Study on the relationship of iodine nutritional status with thyroid function and autoantibodies in pregnant women in Baotou

2020 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Yuanyuan Fan ◽  
Yalu Wang ◽  
Chenhui Li ◽  
Ziling Li
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Thyroid Peroxidase ◽  
Urinary Iodine Concentration ◽  
Iodine Excess ◽  
The Difference ◽  
Relationship Of

Objective: To investigate the relationship of iodine nutritional status with thyroid function in pregnant women in Baotou, and provide a scientific basis for the guide of reasonable iodine supplementation.Methods: By use of As-Ce catalysis spectrophotometry, the urinary iodine concentration was determined in 90 women during different periods of pregnancy admitted to Baogang Hospital of Inner Mongolia from January 2017 to December 2017. The determination of thyroid function and the autoantibody level was carried out by electro-chemiluminescence immunoassay (ECLIA).Results: In the early trimester of pregnancy, pregnant women with iodine deficiency, iodine sufficiency and iodine excess accounted for 36.67%, 40.00% and 23.33% respectively; in the middle trimester of pregnancy, they accounted for 66.67%, 26.67% and 6.66% respectively; they made up 40.00%, 40.00% and 20.00% respectively in the late trimester of pregnancy. The rate of iodine deficiency in women in the middle trimester of pregnancy was significantly higher than that in women in the early and the late trimesters of pregnancy respectively, and the difference was statistically significant (p < .05). The rate of iodine deficiency in pregnant women was positively correlated to the positivity of thyroid peroxidase antibody. Moreover, it had no relationship with the positivity of thyroglobulin antibody. No matter in the pregnant women with iodine deficiency or with iodine excess, the abnormality rate of thyroid function and autoantibodies was significantly higher than that in the pregnant women with iodine sufficiency. The difference was statistically significant (p < .05).Conclusions: The iodine deficiency in the women in the middle trimester of pregnancy is more severe than that in the women in the early and the late trimesters of pregnancy. Iodine deficiency during pregnancy is positively correlated with the positivity of thyroid peroxidase antibody. Pregnant women with iodine deficiency and iodine excess show a higher abnormality rate of thyroid function and autoantibodies. It is recommended to advocate health education on iodine nutrition to pregnant women, and conduct the dynamic monitoring of urinary iodine concentration and the screening of thyroid function and autoantibodies during pregnancy.

scholarly journals Thyroid Function and Thyroglobulin Level in Iodine-Deficient Children of Eastern Nepal

2021 ◽  
Vol 9 (1) ◽  
pp. 75-78
Author(s):  
Saroj Kunwar ◽  
Saroj Khatiwada ◽  
Basanta Gelal ◽  
Saroj Thapa ◽  
Gaurishankar Shah ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Overt Hypothyroidism ◽  
Urinary Iodine Concentration ◽  
Free Triiodothyronine ◽  
Iodine Nutrition ◽  
Serum Thyroglobulin ◽  
Cross Sectional

Iodine deficiency during childhood affects physical and mental development. Iodine deficiency or excess both can negatively impact thyroid function. We conducted this study to assess iodine nutrition and thyroid function in children with insufficient urinary iodine concentration. A community-based cross-sectional study was conducted among the selected schools of Udayapur district. Urinary iodine concentration (UIC) was measured in 1012 school children (6-14 years). Based on UIC data, 83 blood samples were collected to measure serum thyroglobulin (Tg), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). UIC was measured by ammonium persulfate digestion method, and Tg, TSH, fT4, and fT3 were measured using ELISA kits. The median UIE was 236 µg/L, and 11.1% of the children had insufficient UIC. The mean fT3, fT4, and TSH in children with insufficient UIC were 2.55±0.43 pg/mL, 0.96±0.28 ng/dL, and 3.60±1.44 mIU/L respectively. Among children with low UIC levels, the median Tg was 17.5 ng/mL. Overt hypothyroidism was seen in 6%, and subclinical hypothyroidism in 3.6%. The children had sufficient iodine nutrition, and the frequency of thyroid dysfunction was low among the children with insufficient UIC.

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

2019 ◽  
Vol 16 (1) ◽  
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.

scholarly journals High Iodine Deficiency among Pregnant Women in Periurban Ghana: A Hospital-Based Longitudinal Study

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
David Larbi Simpong ◽  
Yaw Asante Awuku ◽  
Kenneth Kwame Kye-Amoah ◽  
Martin Tangnaa Morna ◽  
Prince Adoba ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Pregnant Women ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Clinical Information ◽  
Iodine Concentration ◽  
Iodized Salt ◽  
Urinary Iodine Concentration ◽  
Study Cohort ◽  
Iodine Sufficiency

Background. Iodine deficiency causes maternal hypothyroidism which can lead to growth, cognitive, and psychomotor deficit in neonates, infants, and children. This study examined the iodine status of pregnant women in a periurban setting in Ghana. Methods. This longitudinal study recruited 125 pregnant women by purposeful convenience sampling from the antenatal clinic of the Sefwi Wiawso municipal hospital in Ghana. Urinary iodine concentration (UIC) was estimated by the ammonium persulfate method at an estimated gestational age (EGA) of 11, 20, and 32 weeks. Demographic information, iodized salt usage, and other clinical information were collected using a questionnaire. Results. The prevalence of iodine deficiency among the pregnant women was 47.2% at EGA 11 and 60.8% at both EGA of 20 and 32, whereas only 0.8% of participants not using iodized salt had iodine sufficiency at EGA 32. 18.4%, 20%, and 24% of participants using iodized salt had iodine sufficiency at EGA 11, 20, and 32, respectively. Conclusion. A high prevalence of iodine deficiency was observed among our study cohort.

scholarly journals Two Sources of Maternal Iodine Intake and Their Effect on Maternal and Infant Iodine Status and Thyroid Function and Infant Information Processing in Southern Ethiopia (P11-007-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Tafere Gebreegziabher ◽  
Barbara Stoecker
Keyword(s):  
Information Processing ◽  
Thyroid Function ◽  
Visual Information ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Thyroid Stimulating Hormone ◽  
Iodized Salt ◽  
Southern Ethiopia ◽  
Urinary Iodine Concentration ◽  
Iodine Supplementation

Abstract Objectives The objective of this study was to assess the effects of two sources of iodine supplementation on maternal and infant thyroid function and on visual information processing (VIP) of infants in southern Ethiopia Methods A community-based, randomized, supplementation trial was conducted. Mother infant dyads (n = 106) were recruited within the first week after delivery to participate in this study. Mothers were randomly assigned either to receive a potassium iodide capsule (225 µg iodine) daily for 26 weeks or appropriately iodized salt weekly for 26 weeks for household consumption. Maternal thyroxine (T4), triiodothyronine (T3), thyroid stimulating hormone (TSH), thyroglobulin (Tg), urinary iodine concentration (UIC), breast milk iodine concentration (BMIC) and infant T4, TSH, UIC and VIP were measured as outcome variables. Results At baseline, neither mothers nor infants in the two groups (capsule and iodized salt groups) were significantly different in any of the biomarkers and anthropometry measurements. Maternal TSH and goiter rate significantly decreased following iodine supplementation but T3, T4 and Tg didn't change. Maternal UIC and BMIC and infant UIC were not different among groups. Conclusions A maternal dose of 225 µg iodine daily or adequately iodized salt initiated within a week after delivery decreased goiter and TSH but did not impact infant T4, TSH or VIP. The two treatment groups didn't differ in any of the outcome variables. Funding Sources The study was funded by Nestlé Foundation and Oklahoma State University.

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

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Norman Blumenthal ◽  
Karen Byth ◽  
Creswell J. Eastman
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Blood Collection ◽  
Antenatal Visit ◽  
Urinary Iodine Concentration ◽  
Cross Sectional

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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