ArticleThe American journal of clinical nutrition2015
Gestational changes in iodine status in a cohort study of pregnant women from the United Kingdom: season as an effect modifier.
Article in The American journal of clinical nutrition, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 37 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
37 citing papers in PubMed, 2 syntheses or guidelines pooled it, 70 citations in OpenAlex.
- Dairy Intake and Iodine Status in Pregnant and Lactating Women: A Systematic Review and Meta-Analysis.Nutrients · 2025Pooled it
- Insufficient iodine intake in pregnant women in different regions of the world: a systematic review.Archives of endocrinology and metabolism · 2019Pooled it
- Utilization of adequately iodized salt and iodine status of pregnant women attending antenatal care in Hargeisa, Somaliland: facility based cross-sectional analysis.BMC pregnancy and childbirth · 2026Article
- Article
- Iodine status of pregnant women in the Chinese plateau area - effects on thyroid function as well as adverse pregnancy and fetal outcomes.Asia Pacific journal of clinical nutrition · 2025Article
- Article
- A comparison of the nutritional content and price between dairy and non-dairy milks and cheeses in UK supermarkets: A cross sectional analysis.Nutrition and health · 2024Article
- Iodine and plant-based diets: a narrative review and calculation of iodine content.The British journal of nutrition · 2024Review
- Exploration of the optimal range of urinary iodine concentration in Chinese pregnant women in mildly iodine-deficient and -sufficient areas.European journal of nutrition · 2022Article
- Evaluation of iodine nutritional status during pregnancy by estimated 24-h urinary iodine excretion: population variation range and individual accuracy.Public health nutrition · 2022Article
- Iodine nutrition status and thyroid autoimmunity during pregnancy: a cross-sectional study of 4635 pregnant women.Nutrition journal · 2022Article
- Dairy as a Source of Iodine and Protein in the UK: Implications for Human Health Across the Life Course, and Future Policy and Research.Frontiers in nutrition · 2022Review
- The association of urine markers of iodine intake with development and growth among children in rural Uganda: a secondary analysis of a randomised education trial.Public health nutrition · 2021Article
- Iodine monitoring models contribute to avoid adverse birth outcomes related more than adequate iodine intake.BMC pregnancy and childbirth · 2021Article
- Iodine status of pregnant women with obesity from inner city populations in the United Kingdom.European journal of clinical nutrition · 2021Article
- Article
- Prevalence of inadequate and excessive iodine intake in a US pregnancy cohort.American journal of obstetrics and gynecology · 2021Article
- Impact of Dietary Habit, Iodine Supplementation and Smoking Habit on Urinary Iodine Concentration During Pregnancy in a Catalonia Population.Nutrients · 2020Observational
- Iodine status of teenage girls on the island of Ireland.European journal of nutrition · 2020Article
- Is iodized salt efficient to overcome iodine deficiency in pregnants?Turkish journal of obstetrics and gynecology · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 1 institution in 1 country.
Funding
Abstract
backgroundIodine is required throughout pregnancy for thyroid hormone production, which is essential for fetal brain development. Studies of iodine status in pregnant women from the United Kingdom (UK) have focused on early gestation (<16 wk). Data on the effect of advancing gestation on urinary iodine excretion are conflicting, with suggestions of both an increase and a decrease.
objectivesThe aims were to evaluate iodine status in a cohort of UK pregnant women and to explore how it changes throughout gestation.
designWe used samples and data from 230 UK pregnant women who were recruited to the Selenium in PRegnancy INTervention study. Iodine concentration was measured in spot-urine samples that were collected at ∼12, 20, and 35 wk of gestation; creatinine concentration was also measured to correct for urine dilution. A linear mixed model was used to explore the effect of gestational week on iodine-to-creatinine ratio, with change in season, body mass index, daily milk intake, and maternal age controlled for.
resultsThe median urinary iodine concentration from urine samples collected at all time points (n = 662) was 56.8 μg/L, and the iodine-to-creatinine ratio was 116 μg/g, thus classifying this cohort as mildly-to-moderately iodine deficient. The median iodine-to-creatinine ratios at 12, 20, and 35 wk were 102.5, 120.0, and 126.0 μg/g, respectively. Only 3% of women were taking iodine-containing prenatal supplements. The iodine-to-creatinine ratio increased with advancing gestation, and there was a significant interaction between gestational week and season (P = 0.026). For a 1-wk increase in gestation, the iodine-to-creatinine ratio increased by a factor of 1.05 (95% CI: 1.02, 1.08) in winter and by a factor of 1.04 (95% CI: 1.00, 1.08) in summer.
conclusionsThis group of UK pregnant women was mildly-to-moderately iodine deficient at all trimesters, which is of public health concern. The finding that the iodine-to-creatinine ratio increased over the course of gestation may not be generalizable to populations with different iodine status from ours and merits further investigation. This trial was registered at www.isrctn.com as ISRCTN37927591.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.