Tehran University of Medical Sciences

Science Communicator Platform

Stay connected! Follow us on X network (Twitter):
Share this content! On (X network) By
Do Maternal Urinary Iodine Concentration or Thyroid Hormones Within the Normal Range During Pregnancy Affect Growth Parameters at Birth? a Systematic Review and Meta-Analysis Publisher Pubmed



Nazeri P1 ; Shabbidar S2 ; Pearce EN3 ; Shariat M4
Authors
Show Affiliations
Authors Affiliations
  1. 1. Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
  2. 2. Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
  3. 3. Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA, United States
  4. 4. Family Health Institute, Maternal, Fetal and Neonatal Research Center, Tehran University of Medical Sciences, Tehran, Iran

Source: Nutrition Reviews Published:2020


Abstract

Context: Iodine, an essential constituent of thyroid hormones, is required for proper growth and development. Objective: To investigate whether growth parameters at birth are associated with maternal urinary iodine concentration (UIC) or normal ranges of thyroid hormones during pregnancy. Data Sources: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, electronic databases (namely, MEDLINE, Web of Science, the Cochrane Library, Scopus, and Google Scholar) were searched between January 1988 and November 2018 to identify relevant articles. Data Extraction: Data from the studies included were independently extracted by 2 investigators using standardized forms developed for this review. Data Analysis: The pooled mean birth weight, length, and head circumference values, and 95% confidence intervals were estimated in newborns born to women with UIC<150 and UIC ≥150 lg/L during pregnancy. Possible linear or nonlinear associations between maternal UIC and the aforementioned anthropometric measures were evaluated. A narrative synthesis of the data was performed for thyroid hormones with levels within the normal range. Results: Of the 123 studies identified, 11 were eligible for inclusion in the meta-analysis. The pooled mean birth weight, length, and head circumference in newborns whose mothers had UIC<150 μg/L vs UIC ≥150 μg/L were 2898 g vs 2900 g (P=0.970), 49.6 cm vs 49.4 cm (P=0.880), and 34.0 cm vs 34.1 cm (P=0.933), respectively. Dose-response meta-analyses revealed no significant linear or nonlinear associations between maternal UIC during pregnancy and anthropometric measures at birth. Among the different thyroid function parameters evaluated, high-normal values of maternal free thyroxine and thyrotropin during pregnancy were inversely associated with neonatal birth weight. Conclusion: This systematic review showed that birth weight may be affected by even mild variations in the normal concentrations of maternal thyroid hormones. However, in the current meta-analysis, birth anthropometric measures were not associated with maternal UIC during pregnancy. © The Author(s) 2020.
Related Docs
View other Related Docs
1. Is There an Association Between Thyrotropin Levels Within the Normal Range and Birth Growth Parameters in Full-Term Newborns?, Journal of Pediatric Endocrinology and Metabolism (2018)
2. Effects of Iodine Supplementation During Pregnancy on Pregnant Women and Their Offspring: A Systematic Review and Meta-Analysis of Trials Over the Past 3 Decades, European Journal of Endocrinology (2021)
3. Lactating Mothers and Infants Residing in an Area With an Effective Salt Iodization Program Have No Need for Iodine Supplements: Results From a Double-Blind, Placebo-Controlled, Randomized Controlled Trial, Thyroid (2018)
4. Maternal Urinary Iodine Concentration and Pregnancy Outcomes: Tehran Thyroid and Pregnancy Study, Biological Trace Element Research (2020)
5. Iodine Deficiency/Excess and Pregnancy Outcomes, Thyroid Diseases in Pregnancy (2022)
6. Thyroglobulin Concentration and Maternal Iodine Status During Pregnancy: A Systematic Review and Meta-Analysis, Thyroid (2020)
7. Maternal Urinary Iodine Concentration and Pregnancy Outcomes in Euthyroid Pregnant Women: A Systematic Review and Meta-Analysis, Biological Trace Element Research (2020)
8. Is There Any Difference Between the Iodine Statuses of Breast-Fed and Formula-Fed Infants and Their Mothers in an Area With Iodine Sufficiency?, British Journal of Nutrition (2018)
Experts (# of related papers)
View all Related Experts
Pantea Nazeri Kahgani (12)
Mamak Shariat (4)
Other Related Docs
9. Do Postpartum Maternal Iodine Status or Supplementation Affect Thyroid Function After Delivery? a Systematic Review and Meta-Analysis, Biological Trace Element Research (2023)
10. Isolated Hypothyroxinemia in Iranian Pregnant Women, the Role of Iodine Deficiency: A Population-Based Cross-Sectional Study, Thyroid (2020)
11. Application of Povdone-Iodine at Delivery Significantly Increases Maternal Urinary Iodine But Not Neonatal Thyrotropin in an Area With Iodine Sufficiency, Journal of Pediatric Endocrinology and Metabolism (2017)
12. Can an Educational Intervention Improve Iodine Nutrition Status in Pregnant Women? a Randomized Controlled Trial, Thyroid (2017)
13. Is Breast Milk Iodine Concentration an Influential Factor in Growth- and Obesity-Related Hormones and Infants' Growth Parameters?, Maternal and Child Nutrition (2021)
14. Breast Milk Iodine Concentration Rather Than Maternal Urinary Iodine Is a Reliable Indicator for Monitoring Iodine Status of Breastfed Neonates, Biological Trace Element Research (2018)
15. Urinary and Breast Milk Iodine Concentrations in Lactating Mothers and Its Association With Certain Demographic Characteristics in an Area With Iodine Sufficiency, Iranian Journal of Endocrinology and Metabolism (2018)
16. The Impact of Iodine Status on the Recall Rate of the Screening Program for Congenital Hypothyroidism: Findings From Two National Studies in Iran, Nutrients (2017)