Poor Iodine Knowledge, Coastal Region, and Non-Iodized Salt Consumption Linked to Low Urinary Iodine Excretion in Zhejiang Pregnant Women

Salt Reduction and Iodine Fortification Policies Are Compatible: Perspectives for Public Health Advocacy

Cardiovascular diseases account for almost 18 million deaths annually, the most of all non-communicable diseases. The reduction of dietary salt consumption is a modifiable risk factor. The WHO recommends a daily sodium intake of <2000 mg but average consumption exceeds this in many countries globally. Strategies proposed to aid effective salt reduction policy include product reformulation, front of pack labelling, behavioural change campaigns and establishing a low-sodium-supportive environment. Yet, salt for household and processed food use is, in countries wholly or partially adopting a universal salt iodisation policy, the principal vehicle for population-wide iodine fortification. With salt reduction policies in place, there is concern that iodine deficiency disorders may re-emerge. Recognising the urgency to tackle the rising prevalence of NCDs yet not risk the re-emergence and detrimental effect of inadequate iodine intakes, this review lays out the feasibility of integrating both salt reduction and salt iodine fortification strategies. Reducing the burden of health risks associated with an excessive sodium intake or inadequate iodine through population-tailored, cost-effective strategies involving salt is both feasible and achievable, and represents an opportunity to improve outcomes in public health.

Iodine status and knowledge among pregnant and lactating women in Large City in Northern China after nearly 30 years of the universal salt iodization

BACKGROUND

With the implementation of the universal salt iodization, the iodine nutrition for children and adults has been appropriate, but pregnant women are still at risk of iodine deficiency. It is of great public health significance to explore the iodine status and knowledge, and influence factors and the appropriate health education methods among pregnant and lactating women.

METHODS

From January 2022 to December 2023, at least 50 pregnant women and 50 lactating women were randomly selected from the resident population annually in 16 districts of Tianjin, North China. A total of 1671 pregnant women and 1658 lactating women were recruited. All participants' households salt and random urine samples were collected. A questionnaire was conducted to collect data on iodine related knowledge and behaviors as well as needs of health education from all participants. Logistic regression models were constructed to analyze the factors affecting the iodine related knowledge level. We used the Rasch model and the quadrantal graph to analyze the participants' knowledge level on different iodine-related questions and their needs for health education.

RESULTS

The median urine iodine concentration (UIC) of pregnant and lactating women in Tianjin were 152.40 μg/L and 124.60 μg/L. In some districts, the median UIC of pregnant and lactating women below the appropriate range. The iodized salt coverage rate of pregnant and lactating women in Tianjin was 76.12% and 77.40%, respectively. In pregnant and lactating women who did not actively supplement with iodine, the median UIC in those who consumed non-iodized salt were significantly lower than that in those who consumed iodized salt (139.26 μg/L and 154.40 μg/L, P = 0.044; 94.60 μg/L and 123.80 μg/L, P < 0.001). Compared with the low knowledge score group, pregnant women in the high knowledge score group had a higher proportion of iodized salt consumption (71.25% and 78.05%, P = 0.003), and pregnant and lactating women in the high knowledge score group had a higher proportion of actively supplement iodine (44.61% and 55.34%, P < 0.001; 39.26% and 49.78%, P < 0.001). Health education may be the main factor affecting the iodine related knowledge scores for pregnant and lactating women, with adjusted odds ratios (OR) and 95% confidence intervals (CI) of 2.89 (2.30, 3.62) and 2.46 (1.97, 3.07), respectively. Pregnant and lactating women are most expected to acquire knowledge through healthcare professionals (72.11%) and wechat/website (74.91%), respectively.

CONCLUSIONS

Pregnant and lactating women in some areas of Tianjin are at risk of iodine deficiency. Iodized salt consumption is an important way to ensure iodine nutrition of the population, and the lack of iodine related knowledge is an important factor affecting the consumption of iodized salt. Health education in different ways can be carried out for different people to improve the acceptance and efficiency of health education.

Low Iodine Nutrition Knowledge in Chinese Breastfeeding Women despite Adequate Iodine Status

There has been a scarcity of evidence about iodine nutrition knowledge among women during pregnancy and lactation. The aim of this study was to determine women's iodine knowledge and the relationship between knowledge and iodine status during pregnancy and lactation. Women were recruited from a hospital in the western part of China in the third trimester of pregnancy and followed until the end of the first week of lactation. The women's iodine status was measured by their urinary iodine concentration (UIC) and an iodine-specific, validated food frequency questionnaire (FFQ). Iodine nutrition knowledge was assessed using an iodine nutrition knowledge questionnaire. A total of 200 women (mean age of 29.0 ± 4.2 years) completed the whole study. The majority of the women did not consume enough iodine during both pregnancy and lactation (231.89 vs. 237.26 µg/day). The overall mean iodine knowledge scores in our sample of women during pregnancy and lactation were 4.77 and 4.87, indicating low iodine knowledge. The use of iodized salt and a higher education level were significantly associated with an increased iodine knowledge score. In conclusion, this study reported poor iodine nutrition knowledge in women, highlighting a public health concern. Therefore, the iodine knowledge of women should be improved, possibly via maternal health campaigns to avoid the consequences of iodine deficiency disorders in newborns.

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

OBJECTIVE

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.

DESIGN

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).

SETTING

A cross-sectional study involving pregnant and lactating women in Xinjiang, China was conducted.

PARTICIPANTS

A total of 1181 pregnant women and 504 lactating women were enrolled in the study.

RESULTS

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.

CONCLUSION

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.

Knowledge and practices of pregnant women about iodized salt and its availability in their households in Hawassa city. Community-based cross-sectional study

Objectives:

This study was aimed to assess the knowledge and practices of pregnant women about iodized salt and its availability in their households in Hawassa city, Ethiopia

Methods:

A community-based cross-sectional study design was conducted among pregnant women with a total sample size (N) = 553 in Hawassa city. A multi-stage sampling technique was employed. First, four sub-cities of Hawassa city (out of eight sub-cities) were selected using the lottery method. Households of pregnant women in each selected sub-city were identified and screened. Finally, representative samples were drawn using systematic random sampling technique.

Results:

A total of 537 pregnant women was included, a response rate of 97.1%. This was due to incomplete data for nine and participation refusal for seven participants. The mean age of the participants was 26.98 ± 4.75 years. About 52.51% and 52.33% of the respondents had good knowledge and good salt handling practices, respectively. Regarding availability of iodized salt, 65.55% of pregnant women (31.66% salt with iodine level ⩾15 parts per million (ppm) and 33.89% salt with iodine level <15 ppm) had iodized salt and the remaining 34.45% non-iodized salt (0 ppm) respectively.

Conclusion:

Availability of iodized salt in households of pregnant women was 65.55% (>0 ppm). More than one-third of pregnant women in Hawassa city are utilized non-iodized salt (0 ppm). Nearly half of the pregnant women in Hawassa city had poor knowledge and poor practice about iodized salt. Hawassa city Health Department along with concerned stakeholders should invest more effort to increase awareness about iodized salt and how to handle it safely in households.

The Characteristics of Iodine Nutrition Status in China After 20 Years of Universal Salt Iodization: An Epidemiology Study Covering 31 Provinces

Background: Despite the implementation of the universal salt iodization (USI) program for correction of iodine deficiency in China for ∼20 years, the actual iodine nutrition status of Chinese residents and the prevalence of iodine deficiency and iodine excess are issues that need to be addressed. This nationally representative cross-sectional study was conducted across all 31 provinces of mainland China to gather extensive data on iodine nutrition status and the influential factors. Methods: This study included 78,470 participants, aged 18 years or older, who were interviewed and asked to answer a questionnaire. Urine iodine concentration (UIC) was measured by the inductively coupled plasma mass spectrometry method, and goiter was examined by thyroid ultrasonography. In addition, sixty 9-11 years old school children in each province were randomly selected to evaluate the UIC and thyroid ultrasonography. The iodine nutrition status was determined according to the World Health Organization guidelines. Results: The iodized salt coverage was 95.37%. The median urine iodine (MUI) was 177.89 μg/L (interquartile range [IQR], 117.89-263.90 μg/L) and goiter prevalence was 1.17% (confidence interval [95% CI 0.95-1.43]) in the adult population. The MUI was 199.75 μg/L (IQR, 128.41-303.37 μg/L) in school-age children, and goiter prevalence was 3.50% [95% CI, 2.93-4.13]. The percentage of individuals with UIC <50 μg/L was 3.43%, <20%. Analysis indicated that sex, age, geographic factors, body mass index, and smoking habits influence the iodine nutrition level. Conclusion: The mandatory USI program has successfully eliminated iodine deficiency disorders, and the findings indicate that the iodine nutrition level in the general population is within the safe range.

Low Iodine Intake May Decrease Women's Fecundity: A Population-Based Cross-Sectional Study

Salt iodization is one of the most cost-effective strategies to eliminate iodine deficiency disorders (IDD). However, China’s dismantling of salt monopoly has reduced the availability of iodized salt in the susceptible population in pregnancy, which might cause IDD and have adverse health effects on both themselves and their offspring. The aim of our study was therefore to explore the association between IDD and women’s reproductive health. This is a population-based cross-sectional study conducted in 2018 in Zhejiang Province, China. A total of 1653 pregnant women participated in this study. Median urinary iodine concentration (UIC) in the population was used to assess iodine intake. Cox regression analyses were used to estimate the association between iodine intake and time to pregnancy, which was indicated with fecundability ratio (FR) and 95% confidence interval (CI). The percentage of participants with iodine deficiency who had been waiting longer than 13 months to get pregnant (20%; median UIC 119.6 μg/L) was significantly higher than those with iodine sufficiency (14%; median UIC 147.1 μg/L). A significant decrease in fecundity was observed in participants with iodine deficiency (FR, 0.820; 95% CI, 0.725−0.929) than those with iodine sufficiency. These findings indicate the importance of ongoing monitoring of iodine nutrition in women of reproductive age. Keeping a safe and optimal level of iodine nutrition during pregnancy should be emphasized.

Knowledge, attitude and behaviour of university students regarding salt and iodine: a multicentre cross-sectional study in six countries in Europe and Asia

Background

Strategies to reduce salt intake are encouraged to be implemented in parallel with those that aim to ensure iodine adequacy at the population level. The aim of the present study was to assess and compare knowledge, attitudes and behaviours related to salt and iodine among students in Europe and Asia.

Methods

A multicentre cross-sectional study was conducted with 2459 university students in total (42.7% males, median age 21 years) from four countries in Europe and two countries in Asia. Data were collected with the use of a self-administered questionnaire, and univariate and multivariate statistical analyses were performed to explore any association between variables.

Results

Only 6.5% of all participants knew the correct salt recommendations. Nearly a quarter of them (24.4%) found salt recommendations confusing and/or contradictory. There were significant differences between European and Asian participants, with those from Europe being better informed about salt recommendations, but significantly less knowledgeable about iodine. The reported frequency of use of salt and salt-containing sauces either at the table or for cooking, as well as knowledge about ways to reduce salt intake among those who indicated to make conscious efforts to do so, differed significantly between countries. Significant differences between countries were also observed with respect to the type of salt used, with about one third of all participants (34%) not being aware of the kind of salt they used.

Conclusion

The results of this survey highlight serious salt- and iodine-related knowledge gaps among university students in Europe and Asia. Raising awareness and conducting information campaigns is needed to promote changes in behaviour that would result in a reduction of salt intake and conscious use of iodised salt at the individual level.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-021-00593-5.

Supplemental iodine-containing prenatal multivitamins use and the potential effects on pregnancy outcomes in a mildly iodine-deficient region

PURPOSE

The use and contribution of prenatal multivitamins (PMV) as iodine source for pregnant women in China, especially in mildly iodine-deficient region, have not been well studied. This study aimed to explore the association between PMV intake during pregnancy and thyroid function in mothers and newborns.

METHODS

We performed a study involving women with a history of taking PMV during pregnancy between January 2013 and October 2015, in Shanghai, a mildly iodine-deficient region. Maternal thyroid function in early and late pregnancy, and neonatal TSH on postnatal d 3 were obtained from medical records. We compared the outcomes in pregnant women who took exclusively iodine-containing PMV (I + PMV) with those who took exclusively non-contained PMV (I- PMV). Propensity score matching (PSM) was used to identify women with similar baseline characteristics.

RESULTS

After PSM, 1280 women in I + PMV and 2560 in I- PMV had similar propensity scores and were included in the analyses. Introduction of I + PMV to women was associated with slightly higher maternal thyroid hormone production (higher maternal FT4, p = 0.01, non-significantly lower TSH, p = 0.79) and lower neonatal TSH levels (p < 0.0001). The frequency of adverse pregnancy outcomes or thyroid dysfunctions did not differ between groups in late pregnancy. Mothers received I + PMV (0.2 SD) had a stronger association of maternal TSH with neonatal TSH than those who received I- PMV (0.1 SD). These effects were only shown in TPOAb-negative mothers, not in TPOAb-positive mothers.

CONCLUSION

TPOAb-positive women display an impaired iodine transport in thyroid and placenta, and this may explain the lack of changes in maternal and neonatal thyroid parameters with I + PMV supplementation in these women. This phenomenon might suggest that these women require different iodine doses or treatment approach in comparison with TPOAb-negative women.

Iodine knowledge is associated with iodine status in Portuguese pregnant women: results from the IoMum cohort study

Lack of knowledge about iodine has been suggested as a risk factor for iodine deficiency in pregnant women, but no studies have addressed this issue in Portugal. So, the aim of this study was to investigate iodine knowledge among Portuguese pregnant women and its association with iodine status. IoMum, a prospective observational study, included 485 pregnant women recruited at Centro Hospitalar e Universitário de S. João, Porto, between the 10th and 13th gestational weeks. Partial scores for knowledge on iodine importance, on iodine food sources or on iodised salt were obtained through the application of a structured questionnaire. Then, a total iodine knowledge score was calculated and grouped into low, medium and high knowledge categories. Urinary iodine concentration (UIC) was measured in spot urine samples by inductively coupled plasma MS. Of the pregnant women, 54 % correctly recognised iodine as important to neurocognitive development, 32 % were unable to identify any iodine-rich food and 71 % presented lack of knowledge regarding iodised salt. Of the women, 61 % had a medium total score of iodine knowledge. Knowledge on iodine importance during pregnancy was positively associated with iodine supplementation and also with UIC. Nevertheless, median UIC in women who correctly recognised the importance of iodine was below the cut-off for adequacy in pregnancy (150 µg/l). In conclusion, knowledge on iodine importance is positively associated with iodine status. Despite this, recognising iodine importance during pregnancy may not be sufficient to ensure iodine adequacy. Literacy-promoting actions are urgently needed to improve iodine status in pregnancy.

Geographical influences on thyroid abnormalities in adult population from iodine-replete regions: a cross-sectional study

The studies on the increasing incidence of thyroid abnormalities are scarce. The aim of this current study was to ascertain the effects of geographical region on thyroid abnormalities under the context of universal salt iodization (USI). We randomly selected 1255 participants residing in inland and 1248 in coast, with the determination of urinary iodine concentration (UIC) and functional and morphological abnormalities of thyroid gland. The median UIC was significantly higher for the inland participants (188.5 μg/L) than the coastal participants (128.5 μg/L; p < 0.001), indicating iodine sufficiency in both populations according to the recommended assessment criteria by the World Health Organization. However, the spectrum of thyroid abnormalities varied between regions, with hypothyroidism prevalent in inland and thyroid nodules in coast. The associations between region and thyroid abnormalities via binary logistic regression models showed that the coastal participants were at a higher risk of total thyroid abnormalities than those from the inland (OR 1.216, 95% CI 1.020-1.449), after the adjustment of ten confounders (demographical characteristics, smoking status, metabolism syndrome, and hyperuricemia). These results indicated that further investigations of the adverse effects of hypothyroidism and thyroid nodules on health burden is urgently needed to sustain USI program.

Iodine Deficiency as Assessed by Neonatal TSH in a Sample of Mother-and-Newborn Pairs in Jiangsu Province, China

China has eliminated iodine deficiency disorders since 2011 via the implementation of universal salt iodisation. Following this, a new revised salt iodisation policy was introduced to reduce iodine content in table salt. Since maternal iodine deficiency can lead to cognitive impairment and cretinism in infants, the aim of our study was to assess if the iodine status of pregnant women and neonates was affected by the introduction of new salt iodisation policy. The medical records of the pregnant women and their neonates in the Northern Jiangsu People's Hospital, Yangzhou, Jiangsu Province, China, between January 2018 and May 2018 were reviewed and obtained. Our study included 374 mother-and-newborn pairs. Mean age of the participants was 28 ± 4 years. TSH, FT3 and FT4 of the participants remained within the reference range. The prevalence of thyroid dysfunction was 4.3%. The overall mean neonatal TSH, birth weight and prevalence of low birth weight (LBW) was 2.56 ± 1.59 mIU/L, 3348 ± 465 g and 2.4%, respectively. The prevalence of neonatal TSH values > 5 mIU/L was 8.3%, which suggested the emergence of mild iodine deficiency (i.e. 3.0-19.9%) in our province. In conclusion, although our study reported an improvement of iodine status to mild iodine deficiency in 2017, our pregnant women remained to be iodine deficient. We recommended an ongoing monitoring of iodine status and advocate for the routine iodine supplementation together with iodised salt in Chinese pregnant women.

Association of iodine-related knowledge, attitudes and behaviours with urinary iodine excretion in pregnant women with mild iodine deficiency

BACKGROUND

Subsequent to the implementation of the universal salt iodisation policy, China has all but eliminated the iodine deficiency disorders. However, pregnant women are still experiencing mild iodine deficiency. The present study explored factors that could relate to mild iodine deficiency in pregnant women.

METHODS

In total, 2400 pregnant women were enrolled using a multistage, stratified, random sampling method in Shanghai. Data were collected via a standardised questionnaire. The urine samples and household cooking salt samples were collected for the detection of urinary iodine and salt iodine concentrations.

RESULTS

The median urinary iodine concentration (MUIC) was 148.0 μg L^-1 for all participants, and 155.0 μg L^-1 , 151.0 μg L^-1 and 139.6 μg L^-1 in the first, second and third trimesters. The MUIC in the third trimester was significantly lower than that of the first trimester (P < 0.05). The usage rates of iodised salt and qualified-iodised salt were 71.5% and 59.4%, respectively. Iodine-related knowledge score composition ratio was significantly different between the high and low UIC groups (P < 0.05). Participants' MUIC increased significantly with the increases in iodine-related knowledge score (P < 0.001). The third trimester was a significant risk factor for high UIC, whereas high iodine-related knowledge score, actively learning dietary knowledge and having a habit of consuming iodine-rich food were significant protective factors for high UIC (P < 0.05).

CONCLUSIONS

Iodine level is adequate among pregnant women in Shanghai during the first and the second trimesters, although it is is insufficient in the third trimester. Good iodine-related knowledge, attitudes and behaviours are important for pregnant women with respect to maintaining adequate urinary iodine.

Mild-to-moderate iodine deficiency in a sample of pregnant women and salt iodine concentration from Zhejiang province, China

Since 2011, Zhejiang province has eliminated iodine deficiency disorders (IDD) in its populations. Following this achievement, a new revised iodine concentration in iodised salt was implemented in Zhejiang in 2012. However, the re-emergence of iodine deficiency has been reported in pregnant women. Therefore, the aim of this study was to assess household salt iodine concentration and iodine status of pregnant women in Zhejiang province, China. We conducted a cross-sectional study between April 2018 and August 2018 in Quzhou, Zhejiang province. Pregnant women aged ≥ 18 years who did not have a history of thyroid disease were recruited into the study. They were asked to complete socio-demographic questionnaires including a food frequency questionnaire (FFQ). In addition, a spot urine sample and a household table salt sample were also provided by each participant. A total of 625 pregnant women agreed to participate. The overall median urinary iodine concentration (UIC) was 130 µg/L, indicating mild-to-moderate iodine deficiency in pregnant women. The coverage of iodised salt was 85.2%, and of these, the rate of adequately iodised salt was 98.1%. In conclusion, our results confirmed the re-emergence of iodine deficiency in pregnant women as reported by other studies conducted in Zhejiang province. Therefore, urgent public health actions are needed to improve iodine status of pregnant women in order to prevent the adverse consequences of IDD on the neurodevelopment of foetus.

Adequate Iodine Intake among Young Adults in Jiangsu Province, China Despite a Medium Iodine Knowledge Score

Lack of iodine knowledge might be a risk factor for inadequate iodine intake in populations. Therefore, we aimed to determine the relationship between iodine knowledge and intake in young Chinese adults. A cross-sectional study was conducted in Suzhou, China. Iodine intake was assessed using a validated 33-item iodine-specific Chinese food frequency questionnaire (FFQ) and iodine knowledge was determined using a Chinese iodine knowledge questionnaire. A total of 150 participants (mean age 20.3 years) completed the study. The median iodine intake plus iodized salt was 260 μg/d, indicating iodine sufficiency (>150 µg/d). The median iodine knowledge score was 16/24, suggesting a medium level of knowledge. The majority of participants correctly recognized fish and seafood (95%) and iodized salt (83%) as the most important dietary iodine sources. After adjusting for age and sex, studying in the science cluster and having received iodine education were the predictors of having a higher iodine knowledge score, with adjusted odd ratios (OR) of 4.33 (1.49, 12.61) and 2.73 (1.21, 6.14), respectively. In conclusion, young Chinese adults had an adequate iodine intake despite a medium iodine knowledge score. This study provides support that iodine fortification in China has been successful, but further research is required to more fully substantiate this finding.

Geographical influences on the iodine status in pregnant women, neonates, and school-age children in China

Background

Pregnant women, neonates, and school-age children are vulnerable to iodine deficiency. The iodine contents in the environment (drinking water and household salt for cooking) vary by geographical location in China. The aim of this study was to assess the iodine status in vulnerable groups from different geographical zones and analyze the iodine content in household salt and drinking water from these zones.

Methods

In coastal and inland regions of Zhejiang Province, China, samples of spot urine, drinking water, and household salt for cooking from both pregnant women and school-age children were determined for iodine concentration between 2017 and 2018. Thyroid-stimulating hormone (TSH) levels from neonates born between 2014 and 2015 were acquired from the Newborns Screening Information System. The iodine status of the vulnerable populations was assessed according to the criteria recommended by the World Health Organization.

Results

The median UIC of pregnant women was significantly lower in the coastal region (113.0 μg/L) than the inland region (134.9 μg/L; p < 0.001). The median UICs of pregnant women from these two regions were below the lower optimal iodine cutoff level of 150 μg/L. The percentage of neonates with elevated TSH (> 5 mIU/L) was significantly higher in the coastal region (15.8%) than the inland region (10.5%; p < 0.001). The percentage of neonates with elevated TSH from each region decreased within the range of mild iodine deficiency of 3–19.9%. The median UIC of the coastal school-age children was 156.0 μg/L, and the median UIC of inland children was 181.5 μg/L. Both medians fell within the recommended optimal iodine range of 100–299 μg/L. The iodine concentrations in drinking water varied from 1.0 μg/L in the inland region to 2.0 μg/L in the coastal region. The proportion of households that consumed iodized salt was lower in the coastal region (nearly 65%) than the inland region (approximately 95%).

Conclusions

In these two regions with low iodine contents in drinking water, both pregnant women and neonates were iodine-deficient, although school-age children were iodine-sufficient. Urgent efforts are needed to improve the iodine status of pregnant women and neonates.

Assessment of Iodine Status among Pregnant Women and Neonates Using Neonatal Thyrotropin (TSH) in Mainland China after the Introduction of New Revised Universal Salt Iodisation (USI) in 2012: A Re-Emergence of Iodine Deficiency?

Iodine deficiency during pregnancy can cause iodine deficiency disorders (IDD). However, it is unclear about iodine and thyroid status of Chinese pregnant women and neonates after the implementation of the revised universal salt iodisation (USI) level in 2012. Therefore, the aim of the cross-sectional study was to determine iodine nutrition and thyroid status among pregnant women and their neonates in China after the implementation of USI. Medical records of pregnant women and neonates in Northern Jiangsu People's Hospital between January 2016 and December 2017 were reviewed and included. We included 3060 mother-and-newborn pairs in the study. Mean age of participants was 28.2 ± 4.1 years. TSH, FT3, and FT4 of participants were within normal reference range. The overall mean neonatal TSH, birth weight, and prevalence of low birth weight (LBW) were 4.86 ± 2.06 mIU/L, 3358 ± 455 g, and 3.2%, respectively. The prevalence of neonatal TSH values >5 mIU/L was 29.3%, suggesting iodine deficiency in the region. In conclusion, our results indicated iodine deficiency in the region, according to the neonatal TSH cutoff recommended by WHO/UNICEF/IGD. More efforts are urgently required to improve iodine status of pregnant women in the region in order to prevent a re-emergence of iodine deficiency.