Iodine Supplementation During Pregnancy and Infant Neuropsychological Development INMA Mother and Child Cohort Study

• Published in: American journal of epidemiology Vol. 177; no. 9; pp. 944 - 953
• Main Authors: REBAGLIATO, Marisa, MURCIA, Mario, JULVEZ, Jordi, TARDON, Adonina, BALLESTER, Ferran, ALVAREZ-PEDREROL, Mar, ESPADA, Mercedes, FERNANDEZ-SOMOANO, Ana, LERTXUNDI, Nerea, NAVARRETE-MUNOZ, Eva-María, FORNS, Joan, ARANBARRI, Aritz, LLOP, Sabrina
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 01.05.2013
• Subjects: Biological and medical sciences; Child Development - drug effects; Cognition - drug effects; Cohort Studies; Diet - statistics & numerical data; Dietary Supplements - adverse effects; Epidemiology; Female; Fetal Development - drug effects; Food Analysis; General aspects; Humans; Infant; Interviews as Topic; Iodine - administration & dosage; Iodine - adverse effects; Iodine - urine; Logistic Models; Maternal-Fetal Exchange - drug effects; Medical sciences; Metabolic diseases; Miscellaneous; Multicenter Studies as Topic; Multivariate Analysis; Pregnancy; Psychomotor Performance - drug effects; Public health. Hygiene; Public health. Hygiene-occupational medicine; Spain; Spain; Human; Nutrition; child development; Infant; prenatal nutritional physiological phenomena; Epidemiology; Feeding; Pregnancy; Prenatal; Fetal development; Mother; Cohort study; dietary supplements; Female; Supplementation; Woman; Child; Public health; Food; Food supplement; Iodine; iodine; fetal development
• ISSN: 0002-9262; 1476-6256
• DOI: 10.1093/aje/kws333

Iodine supplementation during pregnancy is a common practice in developed countries. However, scant evidence is available regarding the safety and effectiveness of maternal iodine supplementation with regard to child neuropsychological development. We previously reported an inverse association between iodine supplementation and the psychomotor development of infants in a birth cohort from Valencia, Spain. In the present study, we assessed this association in a wider sample of mother and child pairs from 3 other regions in Spain. Neuropsychological development was assessed using the Bayley Scales of Infant Development in 1,519 infants (median age, 16 months) between 2006 and 2009. In multivariate analyses, maternal consumption of 150 μg/day or more of iodine from supplements was related to a 1.5-fold increase in the odds of a psychomotor score less than 85 (95% confidence interval: 0.8, 2.9) and to a 1.7-fold increase in the odds of a mental score less than 85 (95% confidence interval: 0.9, 3.0). Findings previously reported in the Valencia cohort were only partially verified. The results of the present study suggest that, at least in these regions, iodine supplementation does not improve infant neuropsychological development at 1 year of age. Further research is needed on the risks and benefits of supplementary iodine for both maternal thyroid function and child neurodevelopment.