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

Practice of key essential nutrition action messages and associated factors among mothers of children aged six months to two years old in Karat town, Konso zone, South Ethiopia, 2024: a community-based cross-sectional study

Background

Key essential nutrition actions (ENA) messages are a comprehensive and evidence-based nutritional package designed to improve the nutritional status during the critical first 1,000 days of life. The poor practice of ENA contributes significantly to mortality and morbidity related to malnutrition in young children. However, there is a dearth of studies focusing on the practice of key ENA messages among mothers and the factors associated with their practice. Therefore, this study aimed to assess the practice of key ENA messages among mothers of children aged 6 months to 2 years in Karat town, Konso zone, South Ethiopia in 2024.

Methods

A community-based cross-sectional study involving 421 mothers of children aged 6 months to 2 years was conducted in Karat town, Konso zone, South Ethiopia from January 15 to February 29, 2024. Respondents were chosen using computer-generated random numbers. A structured, pretested, and interviewer-administered questionnaire was used to collect data. Following coding and entry into EpiData 3.1, the data were exported to SPSS version 25 for analysis. Logistic regression (bivariate and multivariable) was employed to identify factors influencing mothers' practice of key ENA messages, and statistical significance was set at p < 0.05 with a 95% confidence interval.

Results

The study found that 47.6% (95% CI: 42.8, 52.42%) of mothers demonstrated good practices. Having secondary education or higher, institutional delivery, receiving nutritional counseling during antenatal care (ANC), receipt of postnatal care (PNC) services, having good knowledge, and having a good attitude towards ENA all increase the likelihood of good practice.

Conclusion

This study emphasizes the need for multifaceted interventions to improve ENA practice among mothers residing in Karat town. To effectively address this issue, it is crucial to implement targeted education programs, strengthen postnatal care services, and nutritional counseling into routine antenatal care, promote institutional deliveries, and enhance awareness.

Determination of the Elemental Iodine in Human Breast Milk by Inductively Coupled Plasma mass Spectrometry

Adequate iodine status in lactating women is defined by a maternal median urinary iodine concentration (UIC) ≧ 100 µg/L. However, the above-mentioned criterion does not account for the secretion of iodine into breast milk and could not truly reflect the amount of iodine delivered to the infants. Measuring breast milk median iodine concentration (BMIC) is crucial, but the method to measure BMIC has not been developed and validated in Taiwan. We adopted the ammonia dilution method without prior sample digestion to measure BMIC by inductively coupled plasma mass spectrometry (ICP-MS). Samples and iodate calibrators were prepared into an aqueous solution containing Triton X-100, 0.5% ammonia solution, and tellurium (128Te) as the internal standard. Precision, accuracy, serial dilution, and recovery tests were performed for method validation. The range of intra-assay and inter-assay coefficient of variation for the four human breast milk samples with different iodine concentrations were 3.2-4.7% and 2.3-5.5%, respectively. The standard NIST 1549 milk powder was prepared into three different concentrations of 50 µg/L, 100 µg/L, and 200 µg/L to assess the accuracy; the bias was < 5%. A recovery of 95-105% was achieved for four human breast milk samples spiked with sodium iodide solution. The serial dilution test confirmed linearity up to 0.998. The limit for detection and quantification was 0.78 µg/L and 2.34 µg/L, respectively. The results of the current study confirmed that this ICP-MS method is accurate and reliable in measuring BMIC.

Household Salt Storage and Seasoning Consumption Are Predictors of Insufficient Iodine Status Among Pregnant Women in Southeastern Brazil

Iodine deficiency in pregnancy may lead to adverse maternal and fetal outcomes, including impaired child development. Sociodemographic factors and different dietary habits may be related to iodine status in pregnant women. The aim of this study was to evaluate the iodine status and its predictors among pregnant women in a city of Southeastern Brazil. This cross-sectional study was conducted with 266 pregnant women receiving prenatal care in 8 primary health care units. Sociodemographic, obstetric and health, habits of acquisition, storage and consumption of iodized salt, and dietary iodine intake data were collected through a questionnaire. The iodine content was evaluated in urinary iodine concentration (UIC), household salt and seasonings, and drinking water samples. Pregnant women were categorized into three groups according to the UIC, determined by iodine coupled plasma-mass spectrometry (ICP-MS): insufficient (< 150 μg/L), adequate (150-249 μg/L), and more than adequate iodine nutrition (≥ 250 μg/L). The median (p25-p75) UIC was 180.2 μg/L (112.8-262.7). It was found 38% and 27.8% of insufficient and more than adequate iodine nutrition, respectively. Number of gestations, KI content of supplement, alcohol consumption, salt storage, and frequency of using industrialized seasoning were associated to iodine status. Alcohol consumption (OR = 6.59; 95%CI 1.24-34.87), pack the salt in opened container (OR = 0.22; 95%CI 0.08-0.57), and use industrialized seasoning weekly (OR = 3.68; 95% CI 1.12-12.11) were predictors of iodine insufficiency. The pregnant women evaluated have adequate iodine nutrition. Household salt storage and seasoning consumption were risk factors for insufficient iodine status.

Iodine Deficiency, Maternal Hypothyroxinemia and Endocrine Disrupters Affecting Fetal Brain Development: A Scoping Review

This scoping review critically discusses the publications of the last 30 years on the impact of mild to moderate iodine deficiency and the additional impact of endocrine disrupters during pregnancy on embryonal/fetal brain development. An asymptomatic mild to moderate iodine deficiency and/or isolated maternal hypothyroxinemia might affect the development of the embryonal/fetal brain. There is sufficient evidence underlining the importance of an adequate iodine supply for all women of childbearing age in order to prevent negative mental and social consequences for their children. An additional threat to the thyroid hormone system is the ubiquitous exposure to endocrine disrupters, which might exacerbate the effects of iodine deficiency in pregnant women on the neurocognitive development of their offspring. Ensuring adequate iodine intake is therefore essential not only for healthy fetal and neonatal development in general, but it might also extenuate the effects of endocrine disruptors. Individual iodine supplementation of women of childbearing age living in areas with mild to moderate iodine deficiency is mandatory as long as worldwide universal salt iodization does not guarantee an adequate iodine supply. There is an urgent need for detailed strategies to identify and reduce exposure to endocrine disrupters according to the "precautional principle".

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

BACKGROUND/OBJECTIVES

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.

SUBJECTS/METHODS

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.

RESULTS

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%).

CONCLUSION

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.

Neurodevelopment, nutrition and genetics. A contemporary retrospective on neurocognitive health on the occasion of the 100th anniversary of the National Institute of Nutrition, Hyderabad, India

In celebration of the centenary of the National Institute of Nutrition (NIN), Hyderabad, India (1918-2018), a symposium highlighted the progress in nutrition knowledge made over the century, as well as major gaps in implementation of that knowledge. Brain famine caused by a shortage of nutrients required for perinatal brain development has unfortunately become a global reality, even as protein-calorie famine was largely averted by the development of high yield crops. While malnutrition remains widespread, the neglect of global food policies that support brain development and maintenance are most alarming. Brain disorders now top the list of the global burden of disease, even with obesity rising throughout the world. Neurocognitive health, remarkably, is seldom listed among the non-communicable diseases (NCDs) and is therefore seldom considered as a component of food policy. Most notably, the health of mothers before conception and through pregnancy as mediated by proper nutrition has been neglected by the current focus on early death in non-neurocognitive NCDs, thereby compromising intellectual development of the ensuing generations. Foods with balanced essential fatty acids and ample absorbable micronutrients are plentiful for populations with access to shore-based foods, but deficient only a few kilometres away from the sea. Sustained access to brain supportive foods is a priority for India and throughout the world to enable each child to develop to their intellectual potential, and support a prosperous, just, and peaceful world. Nutrition education and food policy should place the nutritional requirements for the brain on top of the list of priorities.

Breast Milk Iodine Concentration (BMIC) as a Biomarker of Iodine Status in Lactating Women and Children <2 Years of Age: A Systematic Review

Background: Iodine is needed for the production of thyroid hormones, which are essential for infant growth and development. Given that there are wide variations in breast milk iodine concentration (BMIC) and urinary iodine concentration (UIC), it is unclear if BMIC is associated with UIC in populations residing in iodine sufficient or deficient areas. Aim: To investigate if BMIC can be used as a biomarker for iodine status in lactating women and children <2 years of age. Methods: Electronic databases; PubMed, Web of Science and Scopus were searched until year 2021, for studies investigating the relationship between BMIC and UIC. Studies were reviewed for eligibility, according to inclusion and exclusion criteria, followed by data extraction, according to the PRISMA guidelines. Results: Overall, 51 studies met the criteria for inclusion in the systematic review. BMIC ranged from 18 to 1153 µg/L. In iodine-deficient and iodine-sufficient lactating women, BMIC ranged from 26 to 185 µg/L and 15 to 1006 µg/L, respectively. In most studies, the categorisation of iodine status assessed by median UIC was consistent with the categorisation of iodine status assessed by median BMIC cut off of ≥100 µg/L, to determine iodine sufficiency in lactating women and children <2 years of age. Conclusions: The systematic review indicated that BMIC is a promising biomarker of iodine status in lactating women and children <2 years of age. However, these data need to be interpreted cautiously, given the study limitations in the included studies. Future studies should consider investigating the optimal median BMIC, as there is a lack of high-quality observational and intervention studies in lactating women and infants.

Iodine Supplementation in Pregnancy in an Iodine-Deficient Region: A Cross-Sectional Survey

Iodine deficiency is a common problem in pregnant women and may have implications for maternal and child health. Iodine supplementation during pregnancy has been recommended by several scientific societies. We undertook a cross-sectional survey to assess the efficacy of these recommendations in a European iodine-deficient region. Urinary iodine concentrations (UIC) were determined in pregnant women before (n = 203) and after (n = 136) the implementation of guidelines for iodine supplementation in pregnancy. Iodine supplementation (200 μg/day) reduced the proportion of pregnant women with severe iodine deficiency (37.4% to 18.0%, p = 0.0002). The median UIC increased from 67.6 µg/L to 106.8 µg/L but remained below the recommended target level (>150 µg/L) for pregnant women. In conclusion, iodine supplementation in pregnant women improved iodine status in this iodine-deficient region but was insufficient to achieve recommended iodine levels in pregnancy. Additional measures, such as the adjustment of the dose or timing of supplementation, or universal salt iodization, may be needed.

Media use in gynecological and obstetric care and women’s perceived level of education received of lifestyle-related risks: A cross-sectional study

Objective:

The application of media on lifestyle-related risk factors (LRRFs) by healthcare providers to educate women may improve women’s adherence, health literacy, and awareness of LRRFs, as well as offspring’s health outcomes. This study investigated whether exposure to media-based education in gynecological and obstetric care is associated with LRRFs perceived levels of education received during pregnancy and lactation.

Methods:

We conducted a cross-sectional, observational study across 14 randomly generated sample points in the 12 most populated cities in Baden-Württemberg, southwest Germany. Women were recruited from gynecological and obstetric institutions. Participants were 219 women who met our inclusion criteria and completed the quantitative questionnaire. We applied ordinal logistic regression analyses to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of women’s perceived level of education received related to healthcare providers’ exposure to media-based education.

Results:

Media-based education on LRRFs during pregnancy through gynecologists and/or midwives were significantly associated with women’s perceived level of education received (gynecologists: OR = 4.26 (95% CI: 2.04, 8.90; p < .001); midwives: OR = 3.86 (95% CI: 1.66, 8.98; p = .002)). Similar results were found for media-based education through gynecologists and/or midwives on LRRFs during lactation and its association with women’s self-assessed level of perceived level of education received (gynecologists: OR = 4.76 (95% CI: 2.15, 10.56; p < .001); midwives: OR = 7.61 (95% CI: 3.13, 18.53; p < .001)).

Conclusions:

This study suggests that the exposure to media-based education in gynecological and obstetric care increases women’s perceived level of education received of LRRFs during pregnancy and lactation. Therefore, it is recommendable to apply media in gynecological and obstetric care settings.

The Consumption of Food-Based Iodine in the Immediate Pre-Pregnancy Period in Madrid Is Insufficient. San Carlos and Pregnancy Cohort Study

A pre-gestational thyroid reserve of iodine is crucial to guarantee the increased demand for thyroid hormone production of early pregnancy. An iodine intake ≥150 µg/day is currently recommended. The objective of this study was to assess average pre-gestational food-based iodine consumption in pregnant women at their first prenatal visit (<12 gestational weeks), and its association with adverse materno-fetal events (history of miscarriages, early fetal losses, Gestational Diabetes, prematurity, caesarean sections, and new-borns large/small for gestational age). Between 2015–2017, 2523 normoglycemic women out of 3026 eligible had data in the modified Diabetes Nutrition and Complication Trial (DNCT) questionnaire permitting assessment of pre-gestational food-based iodine consumption, and were included in this study. Daily food-based iodine intake was 123 ± 48 µg, with 1922 (76.1%) not reaching 150 µg/day. Attaining this amount was associated with consuming 8 weekly servings of vegetables (3.84; 3.16–4.65), 1 of shellfish (8.72; 6.96–10.93) and/or 2 daily dairy products (6.43; 5.27–7.86). Women who reached a pre-gestational intake ≥150 µg had lower rates of hypothyroxinemia (104 (17.3%)/384 (21.4%); p = 0.026), a lower miscarriage rate, and a decrease in the composite of materno-fetal adverse events (0.81; 0.67–0.98). Reaching the recommended iodine pre-pregnancy intake with foods could benefit the progression of pregnancy.

Association of Salt Iodization and Urine Iodine Concentration in Schoolchildren from Public Schools in Northeast of Brazil

Iodine deficiency (ID) is recognized as a leading risk factor for child development. Universal salt iodization (USI) is an effective and well-established intervention strategy for the prevention of iodine deficiency disorders (IDD). To evaluate the levels of iodine in household salt samples and the urinary iodine concentration (UIC) in schoolchildren aged 6 to 14 years in public schools in Bahia, Brazil. A cross-sectional study was conducted with 1231 students (6 to 14 years old) from 17 public schools in Bahia. The iodine concentration was evaluated in salt and UIC samples. The adapted Sandell-Kolthoff reaction was used to determine urinary iodine levels. A spectrophotometer (UV-Vis) was used to examine the reduction of ceric ammonium sulfate. A standard iodine solution using a potassium iodate was used to extrapolate the iodine concentrations. The total of 665 salt samples had a median iodine concentration of 24 mg/kg (25th-75th percentile 17.0 to 28.5 mg/kg). The largest proportion (79.6%) of salt samples had iodine concentration in the recommended range, 17.6% of the samples presented iodine at a salt concentration below the established level (<15 mg/kg) and a small proportion was above it (2.8%). The general mean urinary iodine concentration (MUIC) was 217.53 ± 28.30 μg/L and median was 205.50 μg/L. The students evaluated and the salt samples analyzed showed satisfactory results, as recommended by Brazilian legislation and nutritional recommendations of the World Health Organization (WHO).

Nutritional status of iodine in pregnant and non-pregnant adolescents assisted at the Family Health Strategy in Vespasiano, MG

Abstract Objectives: to evaluate the nutritional status of iodine in pregnant adolescents, taking into account the increase in the demand for iodine during pregnancy and the absence of iodization strategies for this population. Methods: cross-sectional study conducted with 62 pregnant and 71 non-pregnant adolescents assisted in primary care. The nutritional status of iodine was determined by urinary samples. The iodine concentration in the consumed culinary salt was also evaluated. For the comparative analyses of categorical variables, the Chi-square test was used and for the continuous variables, the Kruskal-Wallis test, considering a 95% confidence interval (CI) and significance level of 5%. Results: the mean iodine concentration in household salt was 25.1 mg/kg (CI95%= 11.1-67.5 mg/kg), with higher mean content in culinary salt in the group of pregnant women (p<0.028). Regarding the nutritional status of iodine, 71% of pregnant adolescents were deficient and 29% iodine-sufficient, with significant difference when compared to 38% of deficiency and 62% of sufficiency in the control group (p<0.001). Conclusions: there was an iodic deficiency among pregnant adolescents, even in the face of higher concentrations of iode in household salt, exposing a paradox between higher consumption and lower sufficiency in this group. Thus, it is suggested to consider iodine supplementation during pregnancy, seeking to minimize the effects of this deficiency on maternal and child health.

Women's Media Use and Preferences of Media-Based Interventions on Lifestyle-Related Risk Factors in Gynecological and Obstetric Care: A Cross-Sectional Multi-Center Study in Germany

This study aimed to investigate factors affecting (1) women’s media use regarding health-related behaviors during pregnancy and lactation, (2) women’s preferences for media format, and (3) the content of media-based interventions on lifestyle-related risk factors during pregnancy and lactation. A cross-sectional observational multi-center study of pregnant and lactating women and women of childbearing age was carried out in 14 randomly selected obstetric and gynecologic care settings in the 12 most populated cities in Baden-Wuerttemberg, South-West Germany. Data from 219 surveyed women showed that older women, pregnant women, and lactating women have a higher probability of using media during pregnancy and lactation, respectively. The majority of women preferred a combination of analog and digital media-based interventions in gynecological (46.9%) and obstetric (47.1%) care settings and at home (73.0%). Women would like to see information brochures and flyers on health-related behaviors during pregnancy and lactation for use in gynecological and obstetric care settings, and for media use at home, they would like to have books. The probability of preferring the favored media formats in gynecological and obstetric care settings and at home were associated with pregnancy status, relationship status, socioeconomic status (SES), ethnicity, and health insurance status. About 80% of the surveyed women preferred media content regarding recommendations for a healthy lifestyle and healthy behavior during pregnancy and lactation. All of the independent variables were associated with the probability of preferring a specific media content. The SES was found to play a major role in the probability of preferring a specific media content, followed by pregnancy status, ethnicity, and health insurance status. The results from our study provide a basis for tailored preventive interventions in gynecological and obstetric care settings and for use at home. The results imply that a woman can be reached before conception, during pregnancy, or during lactation with preventive measures tailored to their requirements; however, acceptance may vary across personal attributes, such as SES, ethnicity, and others.

Iodine supplementation: is there a need?

PURPOSE OF REVIEW

To review the recent data on iodine deficiency, the impact of iodine deficiency on health outcomes and the need for iodine supplementation in at-risk populations, that is, pregnant and lactating women, infants and young children.

RECENT FINDINGS

The 2019 Iodine Global Network Annual Report highlighted that only 23 countries worldwide (including Finland, Germany, and Norway in Europe) were classified as having insufficient iodine intake in 2019, down from 54 in 2003 and 113 in 1993. Even if severe iodine deficiency during pregnancy has a negative impact on cognitive outcomes later in life, the consequences of mild-to-moderate iodine deficiency on child neurodevelopment are controversial. Two 2017 and 2019 Cochrane Systematic Reviews found no evidence that iodine supplementation in women before, during or after pregnancy improved infant and child cognitive development in areas with mild-to-moderate iodine deficiency. Likewise, a 2019 Cochrane systematic review concluded that there was no evidence of a positive impact of iodine supplementation on morbidity, including cognitive impairment, and mortality in preterm infants.

SUMMARY

There is no scientific evidence to support generalized iodine supplementation in mildly to moderately deficient settings not only in pregnant and lactating women but also in infants, either preterm or term, and in young children.

Systematic review and meta-analysis of iodine deficiency and its associated factors among pregnant women in Ethiopia

Background

Iodine deficiency (ID) is a global public health problem and its impact is more pronounced in low-income countries. During pregnancy, iodine requirement is known to elevate sharply, making pregnant women, especially those living in low-income countries highly vulnerable to iodine deficiency. This study aims to assess the prevalence of iodine deficiency and its associated factors among pregnant women in Ethiopia.

Methods

A systematic literature search was performed by using PubMed, CINAHL, Web of science, global health, and Google scholar electronic databases. Two authors independently extracted all the necessary data using a structured data extraction format. Data analysis was done using STATA Version 14. The heterogeneity of the studies was assessed by using I² test. A random-effects model was used to estimate the pooled prevalence and pooled odds ratio. The presence of publication bias was checked using Funnel plot and Egger’s test.

Results

One thousand one hundred and sixteen studies were reviewed and seven studies fulfilling the inclusion criteria were included in the meta-analysis. The meta-analysis of seven studies that included 2190 pregnant women showed a pooled prevalence of iodine deficiency during pregnancy to be 68.76% (95% CI: 55.21–82.31). In a subgroup analysis, the prevalence in Oromia region is 71.93% (95% CI: 54.87–88.99) and in Amhara region is 60.93% (95% CI: 57.39–64.48). Iodized salt use (AOR = 0.18; 95% CI: 0.08–0.44) and 1st trimester pregnancy (AOR = 0.68; 95% CI: 0.47–0.99) were found to have a significant association with iodine deficiency.

Conclusions

The prevalence of iodine deficiency during pregnancy using urine iodine is considerably high in Ethiopia. Using iodized salt is found to reduce the burden. Hence, there is a need to strengthen iodization programs to tackle the problem.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03584-0.

Risk factors of subclinical hypothyroidism and the potential contribution to miscarriage: A review

BACKGROUND

There is no clear cutoff value for thyroid-stimulating hormone (TSH) level that defines subclinical hypothyroidism (SCH). Moreover, TSH levels can be affected by numerous factors. Although mild SCH has been implicated in miscarriage, the relationship between TSH levels and miscarriage remains unelucidated.

METHODS

We reviewed nine known risk factors affecting TSH levels and 28 studies investigating the potential association between mild SCH and miscarriage, examining whether these factors were considered.

MAIN FINDINGS

Among 28 studies that examined whether mild SCH (TSH > 2.5 mIU/L) contributed to miscarriage, thyroid antibodies were measured in only 15. TSH measurement methods were described in 18 studies. Although the iodinated contrast medium used in hysterosalpingography (HSG) is stored in the body for a long time and is a risk factor for mild SCH, only one study described its potential impact on TSH levels. Nine studies, which concluded that mild SCH contributed to miscarriage, had thyroid status evaluated only after the onset of pregnancy, but not before.

CONCLUSION

TSH levels can be significantly affected by patient demographics and health history, country of origin, and fertility treatment. It is important to consider these factors while evaluating mild SCH. It remains unclear how mild SCH contributes to miscarriage.

Effects of Iodine Intake and Nutraceuticals in Thyroidology: Update and Prospects

Iodine is a microelement that is naturally present in some foods, added to others, and available as a dietary supplement [...].

Atmospheric Pollution and Thyroid Function of Pregnant Women in Athens, Greece: A Pilot Study

Exposure to air pollution and, in particular, to nitrogen dioxide (NO₂) or particulate pollutants less than 2.5 μm (PM2.5) or 10 μm (PM10) in diameter has been linked to thyroid (dys)function in pregnant women. We hypothesized that there may be a dose-effect relationship between air pollutants and thyroid function parameters. We retrospectively evaluated thyrotropin (TSH) in 293 women, NO₂, PM2.5 and PM10 levels in Athens. All the women were diagnosed with hypothyroidism for the first time during their pregnancy. Exposure to air pollution for each woman was considered according to her place of residence. Statistical analysis of age, pregnancy weight change, and air pollutants versus TSH was performed with ordinary least squares regression (OLS-R) and quantile regression (Q-R). A positive correlation for logTSH and PM2.5(r = +0.13, p = 0.02) was found, using OLS-R. Further analysis with Q-R showed that each incremental unit increase (for the 10th to the 90th response quantile) in PM2.5 increased logTSH(±SE) between +0.029 (0.001) to +0.025 (0.001) mIU/L (p < 0.01). The other parameters and pollutants (PM10 and NO₂) had no significant effect on TSH. Our results indeed show a dose-response relationship between PM2.5 and TSH. The mechanisms involved in the pathophysiological effects of atmospheric pollutants, in particular PM2.5, are being investigated.

Consequences of Severe Iodine Deficiency in Pregnancy: Evidence in Humans

Iodine is a necessary micronutrient for the production of thyroid hormones and normal human development. Despite the significant worldwide strategies for the prevention and control of iodine deficiency, it is still a prevalent public health issue, especially in pregnant women. Severe iodine deficiency during pregnancy and neonatal period is associated with many major and irreversible adverse effects, including an increased risk of pregnancy loss and infant mortality, neonatal hypothyroidism, cretinism, and neuropsychomotor retardation. We will review the impact of severe iodine deficiency on maternofetal, neonatal, and offspring outcomes. We will also discuss its epidemiology, classification of iodine deficiency severity, and current recommendations to prevent iodine deficiency in childbearing age and pregnant women.