Maternal iodine status in a multi-ethnic UK birth cohort: Associations with child cognitive and educational development.
born in Bradford
child development
cognition
deficiency
iodine
nutrition
pregnancy
Journal
Paediatric and perinatal epidemiology
ISSN: 1365-3016
Titre abrégé: Paediatr Perinat Epidemiol
Pays: England
ID NLM: 8709766
Informations de publication
Date de publication:
03 2021
03 2021
Historique:
received:
11
04
2020
revised:
17
07
2020
accepted:
28
07
2020
pubmed:
2
9
2020
medline:
25
11
2021
entrez:
2
9
2020
Statut:
ppublish
Résumé
Maternal iodine requirements increase during pregnancy to supply thyroid hormones critical for fetal neurodevelopment. Iodine insufficiency may result in poorer cognitive or child educational outcomes but current evidence is sparse and inconsistent. To quantify the association between maternal iodine status and child educational outcomes. Urinary iodine concentrations (UIC) and iodine/creatinine ratios (I:Cr) were measured in 6971 mothers at 26-28 weeks' gestation participating in the Born in Bradford cohort. Maternal iodine status was examined in relation to child school achievement (early years foundation stage (EYFS), phonics, and Key Stage 1 (KS1)), other learning outcomes, social and behavioural difficulties, and sensorimotor control in 5745 children aged 4-7 years. Median (interquartile range) UIC was 76 µg/L (46, 120), and I:Cr was 83 µg/g (59, 121). Overall, there was no strong or consistent evidence to support associations between UIC or I:Cr and neurodevelopmental outcomes. For instance, predicted EYFS and phonics scores (primary outcomes) at the 25th vs 75th I:Cr percentiles (99% confidence intervals) were similar, with no evidence of associations: EYFS scores were 32 (99% CI 31, 33) and 33 (99% CI 32, 34), and phonics scores were 34 (99% CI 33, 35) and 35 (99% CI 34, 36), respectively. In the largest single study of its kind, there was little evidence of detrimental neurodevelopmental outcomes in children born to pregnant women with iodine insufficiency as defined by World Health Organization-outlined thresholds. Alternative functional biomarkers for iodine status in pregnancy and focused assessment of other health outcomes may provide additional insight.
Sections du résumé
BACKGROUND
Maternal iodine requirements increase during pregnancy to supply thyroid hormones critical for fetal neurodevelopment. Iodine insufficiency may result in poorer cognitive or child educational outcomes but current evidence is sparse and inconsistent.
OBJECTIVES
To quantify the association between maternal iodine status and child educational outcomes.
METHODS
Urinary iodine concentrations (UIC) and iodine/creatinine ratios (I:Cr) were measured in 6971 mothers at 26-28 weeks' gestation participating in the Born in Bradford cohort. Maternal iodine status was examined in relation to child school achievement (early years foundation stage (EYFS), phonics, and Key Stage 1 (KS1)), other learning outcomes, social and behavioural difficulties, and sensorimotor control in 5745 children aged 4-7 years.
RESULTS
Median (interquartile range) UIC was 76 µg/L (46, 120), and I:Cr was 83 µg/g (59, 121). Overall, there was no strong or consistent evidence to support associations between UIC or I:Cr and neurodevelopmental outcomes. For instance, predicted EYFS and phonics scores (primary outcomes) at the 25th vs 75th I:Cr percentiles (99% confidence intervals) were similar, with no evidence of associations: EYFS scores were 32 (99% CI 31, 33) and 33 (99% CI 32, 34), and phonics scores were 34 (99% CI 33, 35) and 35 (99% CI 34, 36), respectively.
CONCLUSIONS
In the largest single study of its kind, there was little evidence of detrimental neurodevelopmental outcomes in children born to pregnant women with iodine insufficiency as defined by World Health Organization-outlined thresholds. Alternative functional biomarkers for iodine status in pregnancy and focused assessment of other health outcomes may provide additional insight.
Substances chimiques
Iodine
9679TC07X4
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
236-246Subventions
Organisme : Medical Research Council
ID : MC_PC_17210
Pays : United Kingdom
Organisme : Department of Health
ID : RP-PG-0407-10044
Pays : United Kingdom
Organisme : Department of Health
ID : PR-R10-0514-11004
Pays : United Kingdom
Informations de copyright
© 2020 The Authors. Paediatric and Perinatal Epidemiology published by John Wiley & Sons Ltd.
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