Iodine Intake In Pregnant Women Research Articles

Serum iodine concentration and its associations with thyroid function and dietary iodine in pregnant women in the southeast coast of China: a cross-sectional study.

Iodine deficiency is a major public health problem in pregnant women. Serum iodine (SI) may represent a useful biomarker for iodine nutrition evaluation. We aimed to assess the relationship between serum iodine concentration (SIC) and urinary iodine concentration (UIC), dietary iodine, thyroid function, and thyroid diseases in pregnant women in the southeast coast of China, and to provide a normal reference range of SIC for pregnant women. A multistage random sampling method was used to select the study population. We collected urine and blood samples from pregnant women and determined UIC and SIC as well as thyroid function using Arsenic-Cerium Catalytic Spectrophotometry, inductively coupled plasma mass spectrometry, and Beckman Coulter Access2 chemiluminescent immunoanalyzer and kit, respectively, and administered a questionnaire on dietary iodine intake in pregnant women. There was a significant negative correlation between SI and thyroid-stimulating hormone (TSH) (r = -0.141) and a significant positive correlation between SI and free triiodothyronine (FT3) (r = 0.106), free thyroxine (FT4) (r = 0.236), triiodothyronine (TT3) (r = 0.229), total thyroxine (TT4) (r = 0.433), and dietary iodine intake (r = 0.068). There was a significant difference in SI levels of pregnancy between the second (78.13 μg/L) and third trimester (75.37 μg/L) (p = 0.018). SI levels between inadequate intake (74.58 μg/L) and appropriate intake (77.92 μg/L) groups were statistically different (p = 0.036). Low SIC was a risk factor for the development of hypothyroxinemia (adjusted OR = 3.14, 95% confidence interval: 1.75-5.66). The reference range for SIC in normal pregnant women is 45.03-112.44 μg/L. SI may be a composite indicator of iodine nutritional status and thyroid function.

Iodized Salt May Not Be Sufficient to Guarantee an Adequate Iodine Intake in Pregnant Women.

Adequate iodine intake is of crucial importance in pregnancy to meet the thyroid hormone needs of both mother and fetus. In the present study, undertaken as a part of the surveillance actions following the introduction in Italy of a national salt iodination program in 2005, the iodine intake was investigated in 123 pregnant women and 49 control women living in the same area of central Italy. All the participants were screened for urinary iodine concentration (UIC), serum level of thyrotropin, free-thyroxine, free-triiodothyronine, and thyroid volume. Moreover, they were provided with a questionnaire on the use of iodine-containing salt or supplements. Control women had a median UIC of 102 µg/L, consistent with an iodine sufficiency, while in pregnant women the median UIC value was 108 µg/L, lower than the endorsed UIC of 150 µg/L. In addition, pregnant women showed a significantly increased median thyroid volume compared to controls. Interestingly, the median UIC did not differ between pregnant women not using iodine-containing salt or supplements and those regularly consuming iodized salt alone, while pregnant women with a daily intake of iodine-containing supplements had an adequate median UIC (168 µg/L). In conclusion, the data reported here showed that pregnant women and their fetuses are still exposed to the detrimental effects of iodine deficiency and that the consumption of iodine-containing supplements should be recommended in pregnancy.

Relationship between iodine knowledge and dietary iodine intake in pregnant and lactating women: a cross-sectional study.

This study assessed the iodine knowledge of pregnant and lactating women and the relationship to dietary iodine intake and iodine status. The factors influencing iodine intake were analysed. Basic information and iodine knowledge were collected via a questionnaire. A FFQ assessed dietary iodine intake. The urinary iodine concentration (UIC) was measured using the arsenic-cerium catalytic spectrophotometric determination of iodine in urine (WS/T 107 -2016). A cross-sectional study involving pregnant and lactating women in Xinjiang, China was conducted. A total of 1181 pregnant women and 504 lactating women were enrolled in the study. The median UIC for pregnant and lactating women was 179·27 and 192·81 µg/l, respectively, and the dietary iodine intake was 407·16 and 356·89 µg/d, respectively. Of the pregnant and lactating women, 73·4 % and 82·5 % had medium iodine knowledge, respectively. In pregnant women, iodine knowledge and dietary iodine intake were positively correlated. High iodine knowledge and iodine education were shown to be protective factors for excessive iodine intake in pregnant women. This study demonstrated that the iodine nutritional status of women in Xinjiang was appropriate, and iodine knowledge was at a medium level, but there was confusion about iodine nutrition. Public education is needed to improve iodine knowledge and active iodine supplementation awareness among these populations of women.

Iodine Intake Based on a Survey from a Cohort of Women at Their Third Trimester of Pregnancy from the Bosque County Chile.

Adequate iodine nutrition is fundamental for all humans and is critical during pregnancy and lactation due to iodine forms part of the structure of thyroid hormones (THs) and it is required for THs function. Iodine is a scarce micronutrient that must be obtained from the diet. Sufficient iodine can be found in the nature from seafood and given it is not frequently consumed by Chileans, public health policies state that table salt in Chile must be iodized. Health plans must be monitored to determine if the intake of iodine is being appropriated and the population has not fallen in deficiency or excess. The aim of this work was to evaluate iodine intake in 26 women at the third trimester of pregnancy. Pregnant women are resident from El Bosque a low-income County located in Santiago de Chile. These Chilean pregnant women were recruited by nutritionist at the Centros de Salud familiar (CESFAM). A 24h dietary recall (24h-DR) was applied to them to evaluate iodine intake. Samples of urine and blood were taken by health professionals to analyze parameters of thyroid function and to measure urine iodine concentration (UIC). The survey analysis showed that the iodine consumption in these pregnant women derived mainly from salt, bread and milk and not from seafood. The survey analysis indicated that iodine intake was above the requirements for pregnant women. However, the average UIC indicated that iodine intake was adequate, suggesting the need to find a better parameter to determine iodine intake in pregnant women.

Prevalence of Excessive Iodine Intake in Pregnancy and Its Health Consequences: Systematic Review and Meta-analysis.

The objective was to estimate the prevalence of excessive iodine intake in pregnant women and to investigate the consequences for maternal-fetal health. The systematic review was based on PRISMA. The search was conducted in September 2021 in LILACS, PubMed/MEDLINE, Science Direct, and SCOPUS databases. Observational studies that assessed excessive nutritional iodine status in pregnancy diagnosed by urinary iodine concentration and associated it with biomarkers of thyroid health function were included. Study selection, data extraction, and risk of biased evaluation were performed independently. Meta-analysis was calculated using a fixed and random effect model, and heterogeneity was assessed by the chi-square test. Meta-regressions were performed to identify the causes of heterogeneity using the Knapp and Hartung test. Nine studies were included in the systematic review, and eight in the meta-analysis. The prevalence of excessive iodine intake in 10,736 pregnant women in different regions of the world was 52%. The main implications for pregnant women were hypothyroxinemia, hypothyroidism, and hyperthyroidism. For the newborn, macrosomia and thyroid dysfunction. In addition, drinking water with high iodine intake contributed to excessive iodine intake. Therefore, the prevalence of iodine excess was 52%, with high heterogeneity among studies, explained by trimester of gestation and FT4 level; therefore, the farther the trimester of gestation and the lower the FT4, the higher the prevalence of iodine excess. PROSPERO Registration: CRD420206467 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=206467 ).

Is Dietary Iodine Intake Excessive According to the Theoretical Model of Healthy Dietary Intake Pattern in Pregnant Women and Schoolchildren: Water, Salt, or Food?

Introduction: Iodine deficiency during pregnancy can cause hypothyroidism and goiter; in schoolchildren, it can cause reduced intelligence quotient. In excess, iodine can cause thyroiditis, goiter, and Hashimoto's hypothyroidism. Currently, schoolchildren and pregnant women are classified as risk groups for excessive iodine intake and iodine deficiency, respectively. Thus, determining iodine from all sources of consumption is important for intervention planning.Objective: To construct a theoretical model for the iodine intake of schoolchildren and pregnant women of a city in the Zona da Mata Mineira region, considering a healthy diet, salt consumption and water intake.Methodology: The dietary iodine intake of pregnant women was analyzed based on a dietary iodine table compiled from an international database. A dietary plan was prepared following the Brazilian Food Guide. Iodine concentration of different salt brands sold in local establishments was checked, and drinking water samples from healthcare facilities were analyzed. A descriptive and exploratory statistical analysis was performed and the results were presented in absolute and relative frequencies, and measures of central tendency and dispersion.Results: According to the proposed diet, pregnant women and schoolchildren would have a daily intake of 71.6 μg and 71 μg, respectively. Thirteen salt brands were evaluated, 69.2% complied with the legislation and the mean iodine content was 29.88 mg. The mean concentration of iodine in water was 25 μg iodine/liter and 14 μg iodine/liter, respectively, in summer and autumn. Considering the intake of food, salt, and drinking water according to the proposed dietary plan, the daily intake for pregnant women would be 279.5 and 253.5 μg for schoolchildren.Conclusion: The daily iodine intake of schoolchildren and pregnant women according to this theoretical model was excessive, considering a healthy dietary pattern. This theoretical model can guide actions and public policies aimed at targeting all forms of iodine intake.

Prevalence of insufficient iodine intake in pregnancy worldwide: a systematic review and meta-analysis.

Iodine deficiency in pregnant women is related to impaired foetal growth and development. The objective of this study was to estimate the prevalence of insufficient iodine intake in pregnant women from different regions of the world. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, five electronic databases and Google Scholar grey literature were searched until 10 April 2021. Two reviewers independently conducted article selection, data extraction, and assessment of the risk of bias. Meta-analyses with random effects, subgroup analyses, and meta-regressions were performed. In total, 4639 observational articles were found, with 61 eligible for inclusion. The population consisted of 163,021 pregnant women adults and adolescents, and the overall prevalence of insufficient iodine intake was 53% (95% confidence interval [CI]: 47-60; I2 = 99.8%). Pregnant women who live in insufficient iodine status country had a higher prevalence (86%; 95% CI: 78-93; I² =97.0%) of inadequate iodine nutritional status than to those living in country considered sufficient (51%; 95% IC: 45-57; I² = 99.8%). Despite the progress in iodine fortification policies and periodic monitoring of the iodine nutritional status of the population worldwide, salt iodination alone may not be sufficient to provide adequate iodine status to pregnant women. Thus, other actions may be necessary to improve the nutritional clinical care of pregnant group.

Iodine supplementation for pregnant women: a cross-sectional national interventional study.

Although Iran has been considered iodine replete since 2000, the first national survey of iodine intake among Iranian pregnant women in 2014 indicated that despite the adequate intake of iodine by the general population, this vulnerable group has moderate iodine deficiency. Therefore, in this national cross-sectional interventional study, we aimed to assess the iodine intake and thyroid function of Iranian pregnant women 2 years after implementing national iodine supplementation for this vulnerable group. In this cross-sectional study, we conducted a national interventional survey of pregnant women. A total of 1200 pregnant women (400 women from each trimester) from 12 provinces of Iran were recruited from the antenatal care clinics from October 2018 to March 2019. The median urinary iodine concentration (MUIC), as an indicator of iodine status in three spot urine samples, was measured, along with the serum total T4 (TT4), thyrotropin (TSH), thyroglobulin (Tg), thyroid peroxidase antibody (TPO-Ab), and iodine content of household salt. The mean age of the cohort was 28 ± 6.2years, with the mean gestational age of 22.7 ± 13.0weeks. The overall MUIC (IQR) of pregnant women was 188µg/L (124.2-263µg/L). Also, the MUICs in the three trimesters of pregnancy were 174µg/L (110-254), 175µg/L (116-251), and 165µg/L (114-235), respectively. The MUICs ≥ 150, 100-149, and < 100µg/L were found in 63, 19.8, and 16.2% of the subjects, respectively. The mean TT4 level was 12 ± 4.5µg/dL, and the median (IQR) level of TSH was 2.37 mIU/L (1.66-3.18 mIU/L). According to our local reference range, 118 (10.5%) pregnant women had subclinical hypothyroidism, 6 (0.53%) women had isolated hypothyroxinemia, and 65 (5.7%) women were TPO-Ab positive. Also, the median (IQR) level of Tg was 10.08µg/dL (5.7-20.4µg/dL), and the median iodine content of household salt was 29.6µg/g; the iodine content was ≥ 30µg/g in 85% of household salt. The results showed that more than 95% of households were under iodized salt coverage. The results of this study indicated that iodine supplementation with at least 150µg of iodine per day improved the iodine intake of pregnant women. Except for subclinical hypothyroidism, the prevalence of clinical hypothyroidism, clinical/subclinical thyrotoxicosis, TPO-Ab positivity, and isolated hypothyroxinemia decreased significantly, which emphasizes the importance of iodine supplementation during pregnancy.

Modeling of iodine consumption with industrial processed foods made with iodized salt in the adults and pregnant in Armenia and Moldova

In recent years, significant progress has been made at the global level in eliminating of iodine deficiency. However, until recently, there has been a gap in methods for estimating iodine intake with industrially processed foods (IPF) produced with iodized salt (IS). The aim of this work was to study the iodine consumption with IPF and kitchen salt by the adult population and pregnant women in Armenia and Moldova. Material and methods. For modeling iodine consumption, a special matrix based on MS Excel spreadsheets was used, into which data on the average per capita daily consumption of the main IPF, salt content in IPF, the share of IPF produced with IS in the total volume of their consumption, percentage of households using IS, and the iodine content in salt according to the national standard were entered. Results and discussion. The estimated average daily salt consumption per capita of the adult population of Armenia was 10.6 g. Due to the use of IS in 93% of households and in the production of 82% of bakery products, 7% of cheese, 83% of meat products, 44% of canned vegetables and 5% of pasta, iodine intake in adults was 149% of the recommended daily allowance (RDA). Bakery products and iodized kitchen salt were the main sources of iodine (66 and 70% of the RDA respectively), and the share of other IPF did not exceed 13%. In Moldova, salt consumption was 11.9 g per day. Due to the use of IS for the production of 50% bakery products, 12% of canned vegetables and 20% of pasta, iodine consumption in adults in Moldova amounted to 74% of RDA almost entirely due to bakery products and kitchen salt (37 and 35% of the RDA respectively). The median urinary iodine concentration indicated adequate iodine intake in both countries and was significantly higher in Armenia (242 μg/L) than in Moldova (136 μg/L). A planned 30% reduction in salt intake may lead to an inadequate reduction in iodine intake in pregnant women. Conclusion. Adequate iodine intake among the adult population of Armenia and Moldova is ensured mainly through the use of IS in households and in the production of bakery products.

Change over time in the iodine nutritional status of pregnant women from the Pamplona healthcare region

IntroductionAdequate iodine intake is essential during pregnancy. A previous study of pregnant women from the Pamplona healthcare region showed mild iodine deficiency (mean urinary iodine level, 125mcg/L). This study was intended to ascertain the iodine intake of pregnant women in our region and to analyze the change over time in their iodine nutritional status. MethodsAn observational study of 400 women in their first trimester of pregnancy. An iodine intake questionnaire was administered. To assess iodine status, urinary iodine concentration (UIC) was measured in a simple urine sample, and serum thyroglobulin levels were determined. In addition, thyroid volume was measured by cervical ultrasound examination. ResultsIodized salt was used by 70.5% of all participants (55.3% since the pre-gestational period) and 98.5% of them received iodine-containing supplements (mean dose, 202.6±30.1mcg/day). Mean urinary iodine concentration was 242mcg/L (138.5–415.5mcg/L) and the mean serum thyroglobulin level was 12.3mcg/L (8.3–9mcg/L). Iodized salt intake was associated with higher UICs and lower thyroid volume. No differences were found in any of the tested parameters regarding the intake of dairy products, fish, or eggs. ConclusionsIodine intake by pregnant women in Pamplona has increased due to a greater use of iodized salt and to higher doses of iodine supplements. As a result of this, an adequate iodine status has been achieved in the last decade.

Is iodized salt efficient to overcome iodine deficiency in pregnants?

Objective:Iodine is a trace element that synthesizes thyroid hormones necessary for optimal human growth and development. The relationship between dietary iodine intake and spot urinary iodine excretion in pregnant women has not been previously evaluated in Trabzon city, which is an endemic area of iodine deficiency in the Black Sea region of Turkey. This study aimed to evaluate the relationship between dietary iodine intake and urine iodine excretion in pregnant women.Materials and Methods:This study enrolled 150 pregnant women aged between 19 and 45 years who applied to Clinic of Gynecology and Obstetrics in Trabzon. Spot urine specimens were taken, and dietary iodine intake data were collected using a food frequency questionnaire (FFQ) and 24-hours dietary recall (24-h DR) method.Results:The median urinary iodine concentration (UIC) in the general specimen was 100.6 μg/L. Of the pregnant women, 80.0% had insufficient and 20.0% had sufficient iodine levels, according to UIC. Although total iodine-rich food intake determined by FFQ was sufficient in 20.7% (n=31) of participants, 24-h DR iodine intake was sufficient only 10.7% (n=16). A significant association between urinary iodine excretion and iodine intake was observed in both 24-h DR and FFQ intake estimates (p<0.05). The iodine intake values obtained in both 24-h DR and FFQ and the iodized salt effect were correlated with UIC in all models (p<0.05). Even though 96.0% of pregnant women used iodized salt, its effect on UIC was 15.2%.Conclusion:Both methods indicate that the iodine intake of pregnant women might be insufficient in Trabzon area. Also, although iodized salt use is high in pregnant women in Trabzon, it is not enough to prevent iodine deficiency.

Assessing the impact of drinking water iodine concentrations on the iodine intake of Chinese pregnant women living in areas with restricted iodized salt supply

The supply of non-iodized salt and the water improvement project have been conducted to reduce the iodine concentration in drinking water in areas with elevated water iodine. We aimed to assess the impact of water iodine concentration (WIC) on the iodine intake of pregnant women in areas with restricted iodized salt supply, and determine the cutoff values of WIC in areas with non-iodized salt supply. Overall, 534 pregnant women who attended routine antenatal outpatient visits in Zibo Maternal and Child Health Hospital in Gaoqing County were recruited. The 24-h urine iodine excretion (UIE) in 534 samples and the iodine concentration in 534 drinking water samples were estimated. Urinary iodine excretion, daily iodine intake, and daily iodine intake from drinking water (WII) were calculated. The relationship between WIC and daily iodine take was analyzed. The median WIC, spot urine iodine concentration (UIC), and 24-h UIE were 17 (6, 226) μg/L, 145 (88, 267) μg/L, and 190 (110, 390) μg/day, respectively. A significant positive correlation was found between WIC and UIE (R2 = 0.265, p < 0.001) and UIC (R2 = 0.261, p < 0.001). The contribution rate of WII to total iodine intake increased from 3.0% in the group with WIC of < 10μg/L to 45.7% in the group with WIC of 50-99μg/L. The iodine content in drinking water is the major iodine source in pregnant women living in high-water iodine areas where iodized salt supply is restricted. The contribution rate of daily iodine intake from drinking water increases with the increase in water iodine concentration.

Iodine adequacy in reproductive age and pregnant women living in the Western region of Saudi Arabia

BackgroundDespite the serious maternal and foetal complications associated with iodine deficiency during pregnancy, surveys related to pregnant women in the Kingdom of Saudi Arabia (KSA) are lacking. This study, therefore, measured urine iodine concentrations (UIC) alongside the potential socioeconomic factors contributing towards iodine inadequacy in reproductive age and pregnant Saudi women from the Western province of KSA.MethodsSpot urine samples were collected from 1222 pregnant and 400 age-matched non-pregnant/non-lactating reproductive age women. The socioeconomic characteristics were obtained through a structured questionnaire. The WHO criteria for iodine sufficiency in non-pregnant (100–199 μg/L) and pregnant (150–249 μg/L) women were applied.ResultsThe median UIC in the non-pregnant women (101.64 μg/L; IQR: 69.83–143.55) was at the lowermost WHO recommended cut-off, whereas the pregnant group was iodine deficient (112.99 μg/L; IQR: 81.01–185.57). Moreover, the median UIC was below adequacy across the different trimesters. The use of non-iodised salt significantly increased the risk of iodine deficiency in the non-pregnant (OR = 2.052; 95%CI: 1.118–3.766) and pregnant women (OR = 3.813; 95%CI: 1.992–7.297), whereas taking iodine supplements significantly lowered the risk in both groups (OR = 0.364; 95%CI: 0.172–0.771 and OR = 0.002; 95%CI: 0.001–0.005, respectively). Passive smoking was also an independent risk factor for iodine deficiency in the non-pregnant (OR = 1.818; 95%CI: 1.097–3.014) and pregnant (OR = 1.653; 95%CI: 1.043–2.618) groups. Additionally, BMI correlated independently and significantly with median UIC in the non-pregnant and pregnant populations. However, multiparity (OR = 3.091; 95%CI: 1.707–5.598) and earning below the minimum wage (2.520; 95%CI: 1.038–6.119) significantly increased the risk of iodine deficiency only in the non-pregnant women.ConclusionsThis study is the first to show borderline iodine sufficiency in reproductive age Saudi women from the Western province, whereas mild iodine deficiency was observed in the pregnant population and could represent a serious public health problem. This study also advocates the necessity to establish routine iodine dietary advice services by the health authorities to foster adequate iodine intake in pregnant women to avoid the perilous consequences of iodine deficiency on maternal-foetal health.

Evolución del estado de nutrición de yodo en gestantes del area sanitaria de Pamplona

IntroductionAdequate iodine intake is essential during pregnancy. A previous study of pregnant women from the Pamplona healthcare region showed mild iodine deficiency (mean urinary iodine level, 125 mcg/L). This study was intended to ascertain the iodine intake of pregnant women in our region and to analyze the change over time in their iodine nutritional status. MethodsAn observational study of 400 women in their first trimester of pregnancy. An iodine intake questionnaire was administered. To assess iodine status, urinary iodine concentration (UIC) was measured in a simple urine sample, and serum thyroglobulin levels were determined. In addition, thyroid volume was measured by cervical ultrasound examination. ResultsIodized salt was used by 70.5% of all participants (55.3% since the pre-gestational period) and 98.5% of them received iodine-containing supplements (mean dose, 202.6±30.1 mcg/day). Mean urinary iodine concentration was 242 mcg/L (138.5-415.5 mcg/L) and the mean serum thyroglobulin level was 12.3 mcg/L (8.3-9 mcg/L). Iodized salt intake was associated with higher UICs and lower thyroid volume. No differences were found in any of the tested parameters regarding the intake of dairy products, fish, or eggs. ConclusionsIodine intake by pregnant women in Pamplona has increased due to a greater use of iodized salt and to higher doses of iodine supplements. As a result of this, an adequate iodine status has been achieved in the last decade.

Insufficient iodine intake in pregnant women in different regions of the world: a systematic review.

Insufficient iodine intake in pregnant women in different regions of the world: a systematic review.

Iodine Status of Pregnant Women in Bulgaria

Universal iodization of salt on the whole territory in Bulgaria was introduced in 1994. The external evaluation of an International expert group conducted in 2005, placed the country among those who successfully overcame the problem of iodine deficiency. AIM of the present study is to update the data on iodine intake of pregnant women in Bulgaria, given that there have been no studies in the last 8 years. MATERIAL: A total number of 537 pregnant women were recruited in the study with an average age 30.49±5 y, distributed by gestational weeks and according to the intake of (vitamins and minerals preparations) preparations containing vitamins with minerals. The study was conducted as a cross-sectional, multicenter population-based in 10 regions of Bulgaria (a total of 84 settlements), without pre-selection and 98.3% of the examined pregnant women use Bulgarian iodized salt according to the data from the Questionnaire. METHOD: A spot morning urine samples were collected for determination of urinary iodine concentration. The frozen samples in a special container were transported to the accredited Limbach laboratory in Heidelberg, Germany. The iodine in urine was determined by inductively coupled plasma mass spectrometry (ICP-MS) method. The statistical analysis was performed using standard SPSS 13.0 for Windows. RESULTS: The median urinary iodine concentration (mUIC) for the whole group of pregnant women (n-537) was 170 µg/L (95% CI 161.00 - 177.00). Normal iodine excretion is present in 39.3%, low – in 41.2% and over-optimal – in 19.6% of pregnant women. Significantly lower levels of iodine in urine were found in the third trimester of pregnancy compared to the first trimester (P < 0.012) and compared to the second trimester (P < 0.001). The median iodine concentration in pregnant women from the group supplemented with combined vitamins with minerals was significantly higher compared to the group without supplementation – 175 (95% CI 166.00 - 199.00) against 149 (95% CI 123.00 - 168.00), P < 0.021. CONCLUSION: During pregnancy, additional supplementation with combined vitamins with minerals containing iodine is required, regardless of the universal iodization of salt, introduced in Bulgaria for more than twenty-five years.

Insufficient iodine intake in pregnant women in different regions of the world: a systematic review.

To determine the prevalence of insufficient iodine intake in pregnant women. The search was performed in the electronic databases Medline (PubMed), Latin American and Caribbean Literature in Health Sciences (Lilacs) and Scopus. Review studies, experimental studies, those with adolescent pregnant women (< 20 years) and iodine supplementation were excluded. The selection followed the steps of identifying the articles in the databases, deleting the duplicates, and reading the titles, abstracts, and then the entire article. The search for the articles occurred in September 2017, using the descriptors "pregnant" and "iodine deficiency" NOT "supplementation" in English, Portuguese and Spanish. Thirteen articles were included, the deficiency prevalence ranged from 16.1% to 84.0%, and the median of iodine intake was insufficient in 75% of the studies. There is no classification for mild, moderate or severe levels of iodine deficiency in pregnant women, which makes it impossible to know the real dimension of the problem. The high prevalence of insufficient iodine intake in pregnant women, observed worldwide, shows the need for a population classification in order to direct public policies. Arch Endocrinol Metab. 2019;63(3):306-11.

Excessive iodine intake is associated with formation of thyroid nodules in pregnant Chinese women

In recent decades, the prevalence of thyroid nodules (TNs) has steadily increased in pregnant women. Therefore, this study aimed to investigate associations between TNs and iodine intake in pregnant women. From March 2016 to May 2017, serum and spot urine samples, as well as demographic data and medical history, were collected from 2353 pregnant women. Urine iodine concentration (UIC) and creatinine (Cr) level were determined in spot urine samples; serum thyroid hormones and thyroid autoantibodies were also determined. We examined the hypothesis that excess iodine intake influences incidence of TNs. Herein, TNs were diagnosed by ultrasonography, whereas demographic data and medical history were collected by questionnaire. Multivariate logistic regression models were used to calculate the odds ratios and their corresponding confidence intervals for TN risk factors. Generalized linear mixed model was used to assess the random effects of the regions. The UIC and UIC to creatinine ratio (I/Cr ratio) were significantly higher in pregnant women with TNs (168 and 190 μg/L, respectively, for UIC [P < .01]; 139 and 155 μg/g, respectively, for I/Cr ratio [P < .01]). Thyroglobulin, age, pre-pregnancy body mass index, and iodine-excessive region were associated with TNs (odds ratio = 1.01, 1.06, 1.04, and 2.38, respectively). Whereas I/Cr ratio was not a significant risk factor for TNs in pregnant women when adjusted for potential confounders, iodine excess (I/Cr ratio >500 μg/g) was a risk factor in pregnant women in their second trimester. People living in areas with excessive iodine in drinking water should decrease their iodine intake, and a safe water source should be provided to ensure that the I/Cr ratio of pregnant women can be maintained at an optimal level.

Language delay and poorer school performance in children of mothers with inadequate iodine intake in pregnancy: results from follow-up at 8\xa0years in the Norwegian Mother and Child Cohort Study

PurposeSome studies indicate that mild-to-moderate iodine deficiency in pregnant women might negatively affect offspring neurocognitive development, including previous results from the Norwegian Mother and Child Cohort study (MoBa) exploring maternally reported child development at age 3 years. The aim of this follow-up study was to investigate whether maternal iodine intake in pregnancy is associated with language and learning at 8 years of age.MethodsThe study sample includes 39,471 mother–child pairs participating in MoBa with available information from a validated food frequency questionnaire covering the first half of pregnancy and a questionnaire on child neurocognitive development at 8 years. Multivariable regression was used to explore associations of iodine intake from food and supplements with maternally reported child outcomes.ResultsMaternal iodine intake from food less than ~ 150 µg/day was associated with poorer child language skills (p-overall = 0.013), reading skills (p-overall = 0.019), and writing skills (p-overall = 0.004) as well as poorer school test result in reading (p < 0.001), and increased likelihood of the child receiving special educational services (p-overall = 0.042) (in non-iodine supplement users). Although significant, differences were generally small. Maternal use of iodine supplements in pregnancy was not significantly associated with any of the outcomes.ConclusionsLow habitual iodine intake in pregnant women, i.e., lower than the recommended intake for non-pregnant women, was associated with mothers reporting poorer child language, school performance, and increased likelihood of special educational services. We found no indications of benefits or harm of using iodine-containing supplements in pregnancy. Initiating use in pregnancy might be too late.

Current status of iodine deficiency-related disorders prophylaxis in Slovakia - the life's work of Julian Podoba remained unfinished.

Prophylaxis of iodine deficiency-related disorders with iodized salt in Slovakia was introduced in 1951. This prophylactic measure yielded remarkably good results. Endemic goiter and endemic cretinism disappeared. Sufficient iodine intake, mainly in children and adolescents, was confirmed in several local and international studies carried out in the period 1991-95. Unfortunately, since seventies, there has been no institution which would have dealt with iodine prophylaxis in such an extent as this important measure of Slovak preventive medicine would require. Neither systematic monitoring of iodine intake nor systematic population epidemiological studies have been carried out. We do not have any data on the iodine intake in pregnant women, the most vulnerable population group in relation to the iodine deficiency. During the period June 2014 - October 2015, we examined iodine excretion in 426 probands from three regions of Slovakia with an emphasis on the pregnant women. Iodine intake was found to be sufficient, even more than adequate, in all age groups of Slovak population. The only population group with iodine intake borderline or very mild iodine deficiency are pregnant women. 1/ Iodine nutrition in Slovakia is generally sufficient, even oversteps the requirement, with the exception of pregnant women. Iodine intake in pregnant women should be fortified by iodine containing multivitamin preparations. 2/ We recommend to include the examination of urinary iodine into the screening of thyropathies in early pregnancy. 3/ It is not enough to implement the iodine deficiency-related disorders prevention programs, it is also necessary to stabilize such programs over time and balance the benefits with possible side effects of this program.