Trial reportEuropean journal of nutrition2021
A randomized, double-blind study of iodine supplementation during pregnancy in Sweden: pilot evaluation of maternal iodine status and thyroid function.
Trial report in European journal of nutrition, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT02378246 (The Importance of Iodine During Pregnancy for Future Brain Function), which is not on this map. Cited by 16 papers, 1 of them a synthesis 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.
The Importance of Iodine During Pregnancy for Future Brain Function : a Randomized Placebo-controlled Trial. Swedish Iodine in Pregnancy and Development in Children (SWIDDICH) Study
Who cites it
16 citing papers in PubMed, 1 synthesis or guideline pooled it, 23 citations in OpenAlex.
- Effects of different iodine supplementation strategies on thyroid function in iodine-deficient pregnant women: a meta-analysis.Frontiers in public health · 2026Pooled it
- The relationship between different iodine sources and nutrition in pregnant women and adults.Frontiers in endocrinology · 2022Trial
- Iodine in Health and Disease: A Comprehensive Review.Nutrients · 2026Review
- Key Messages of the Iodine Deficiency Working Group (AKJ): Maternal Hypothyroxinemia Due to Iodine Deficiency and Endocrine Disruptors as Risks for Child Neurocognitive Development.Geburtshilfe und Frauenheilkunde · 2025Article
- The Pathophysiological Mechanisms and Pattern of Dyslipidemia Associated with Iodine Deficiency and Subclinical Hypothyroidism in Pregnant Normotensive and Preeclamptic Central African Women.Pathophysiology : the official journal of the International Society for Pathophysiology · 2025Article
- Iodine nutritional status in different trimesters of pregnancy and its association with dietary habits: a prospective observational study in Taiwan.BMC pregnancy and childbirth · 2025Observational
- Food and nutrient intake at 1 year of age in Northern Sweden: results from the Swedish NICE birth cohort.Frontiers in nutrition · 2025Article
- Micro-nutrient sufficiency in mothers and babies: management of deficiencies while avoiding overload during pregnancy.Frontiers in nutrition · 2025Review
- Thyroid function and iodine intake: global recommendations and relevant dietary trends.Nature reviews. Endocrinology · 2024Review
- Reference Intervals of Serum Iodine Concentration in Chinese Pregnant Women.Biological trace element research · 2024Article
- Iodine Deficiency, Maternal Hypothyroxinemia and Endocrine Disrupters Affecting Fetal Brain Development: A Scoping Review.Nutrients · 2023Article
- A Scoping Review of Iodine and Fluoride in Pregnancy in Relation to Maternal Thyroid Function and Offspring Neurodevelopment.Advances in nutrition (Bethesda, Md.) · 2023Article
- Preconception Counseling in Patients with Hypothyroidism and/or Thyroid Autoimmunity.Medicina (Kaunas, Lithuania) · 2022Review
- Assessment of Joint Impact of Iodine, Selenium, and Zinc Status on Women's Third-Trimester Plasma Thyroid Hormone Concentrations.The Journal of nutrition · 2022Article
- The role of nutrients in human neurodevelopment and their potential to prevent neurodevelopmental adversity.Frontiers in nutrition · 2022Review
- HPLC Analysis of the Urinary Iodine Concentration in Pregnant Women.Molecules (Basel, Switzerland) · 2021Article
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 3 institutions in 1 country.
Funding
Abstract
purposePregnant women in Sweden are mildly iodine deficient. We investigated the effect of daily iodine supplementation on the iodine and thyroid status of pregnant women.
methodsIn this pilot, randomized, double-blind trial, 200 thyroid-healthy pregnant women were recruited at mean (standard deviation) pregnancy week 8.85 (1.62) and assigned (1:1) to daily intake of a multivitamin tablet with or without 150 μg of iodine. Urine and serum samples were collected at baseline and once during the second and third trimesters. Urinary iodine concentration (UIC), serum thyroglobulin (Tg), thyroid-stimulating hormone (TSH), free thyroxine (FT4), and thyroid peroxidase antibodies (TPOabs) were analyzed. Neonatal TSH data were collected. UIC and Tg were also analyzed in a group of 89 thyroid-healthy non-pregnant women of reproductive age (WRA).
resultsAt baseline, the intervention and the control groups had similar median UIC (interquartile range (IQR)): 110 μg/L (74-119) and 111 μg/L (66-168), respectively. The intervention group reached iodine sufficiency with median UIC (IQR) 139 μg/L (89-234) and 136 μg/L (91-211) in the second and third trimester, respectively, without significant difference from the lower limit of the recommended range, i.e. 150-250 μg/L (p = 0.42 and p = 0.87, respectively). The intervention group had higher median UIC and lower median Tg compared to the control group during the second (p < 0.001 and p = 0.019, respectively) and third trimester (p < 0.001 and p = 0.003, respectively), whereas thyroid hormones, serum TPOabs, and neonatal TSH were similar. The WRA group presented median UIC (IQR) 65 μg/L (30-98) and median Tg (IQR) 18 μg/L (13-27).
conclusionA daily supplement containing 150 μg of iodine to a group of pregnant women with mild iodine deficiency improved the iodine status from mild ID to iodine sufficiency. This improvement seems to have had a positive impact on maternal thyroglobulin. This study is now under extension to investigate the children's neuropsychological development.
trial registrationClinicalTrials.gov Identifier NCT02378246, May 3, 2015, retrospectively registered.
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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.