SynthesisThe Journal of clinical endocrinology and metabolism2019
Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data.
Synthesis in The Journal of clinical endocrinology and metabolism, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 64 papers, 6 of them syntheses that pooled it.
What it found
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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
64 citing papers in PubMed, 6 syntheses or guidelines pooled it, 123 citations in OpenAlex.
- Pooled it
- An Evaluation of Food and Nutrient Intake among Pregnant Women in The Netherlands: A Systematic Review.Nutrients · 2023Pooled it
- Association Between Newborn Thyroid-Stimulating-Hormone Concentration and Neurodevelopment and Growth: a Systematic Review.Biological trace element research · 2022Pooled it
- Iodine Status of Women and Infants in Russia: A Systematic Review.International journal of environmental research and public health · 2020Pooled it
- Interference on Iodine Uptake and Human Thyroid Function by Perchlorate-Contaminated Water and Food.Nutrients · 2020Pooled it
- Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data.The Journal of clinical endocrinology and metabolism · 2019Pooled it
- Association of Mild Iodine Insufficiency during Pregnancy with Child Neurodevelopment in Patients with Subclinical Hypothyroidism or Hypothyroxinemia.American journal of perinatology · 2024Trial
- Improved first trimester maternal iodine status with preconception supplementation: The Women First Trial.Maternal & child nutrition · 2021Trial
- Does maternal iodine supplementation during the lactation have a positive impact on neurodevelopment of children? Three-year follow up of a randomized controlled trial.European journal of nutrition · 2021Trial
- Trial
- What Endocrinologists Should Know About Iodine: Population Deficiency, Individual Excess and Misinformation in the United Kingdom.Clinical endocrinology · 2026Review
- Nutrition, Physical Activity and Other Health Aspects Before and During Pregnancy - Recommendations by the Nationwide "Healthy Start Network" (Netzwerk Gesund ins Leben) 2026.Geburtshilfe und Frauenheilkunde · 2026Article
- Plant-Based Diet and Pregnancy-Related Disorders: A Narrative Review.Current nutrition reports · 2026Review
- Iodine deficiency in the first pregnancy trimester and intelligence in adolescence.European journal of nutrition · 2026Article
- Iodine Supplementation Before, During and After Pregnancy.Geburtshilfe und Frauenheilkunde · 2026Article
- Update on the Risk Factors for Thyroid Dysfunction in Pregnancy.Biomedicines · 2026Review
- Critical Role of Iodine and Thyroid Hormones During Pregnancy.International journal of molecular sciences · 2025Review
- Association of Maternal Thyroglobulin With Gestational Thyroid Function and Offspring IQ and Brain Morphology.The Journal of clinical endocrinology and metabolism · 2025Article
- Article
- Essential micronutrients in children and adolescents with a focus on growth and development: a narrative review.Journal of Yeungnam medical science · 2025Article
4 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
15 authors at 8 institutions in 4 countries.
Funding
Abstract
contextAlthough the consequences of severe iodine deficiency are beyond doubt, the effects of mild to moderate iodine deficiency in pregnancy on child neurodevelopment are less well established.
objectiveTo study the association between maternal iodine status during pregnancy and child IQ and identify vulnerable time windows of exposure to suboptimal iodine availability.
designMeta-analysis of individual participant data from three prospective population-based birth cohorts: Generation R (Netherlands), INMA (Spain), and ALSPAC (United Kingdom); pregnant women were enrolled between 2002 and 2006, 2003 and 2008, and 1990 and 1992, respectively.
settingGeneral community.
participants6180 mother-child pairs with measures of urinary iodine and creatinine concentrations in pregnancy and child IQ. Exclusion criteria were multiple pregnancies, fertility treatment, medication affecting the thyroid, and preexisting thyroid disease.
main outcome measureChild nonverbal and verbal IQ assessed at 1.5 to 8 years of age.
resultsThere was a positive curvilinear association of urinary iodine/creatinine ratio (UI/Creat) with mean verbal IQ only. UI/Creat <150 µg/g was not associated with lower nonverbal IQ (-0.6 point; 95% CI: -1.7 to 0.4 points; P = 0.246) or lower verbal IQ (-0.6 point; 95% CI: -1.3 to 0.1 points; P = 0.082). Stratified analyses showed that the association of UI/Creat with verbal IQ was only present up to 14 weeks of gestation.
conclusionsFetal brain development is vulnerable to mild to moderate iodine deficiency, particularly in the first trimester. Our results show that potential randomized controlled trials investigating the effect of iodine supplementation in women with mild to moderate iodine deficiency on child neurodevelopment should begin supplementation not later than the first trimester.
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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.