Prenatal iodine supplementation and early childhood neurodevelopment: the PoppiE trial - study protocol for a multicentre randomised controlled trial

Karen P Best; Jacqueline F Gould; Maria Makrides; Thomas Sullivan; Jeanie Cheong; Shao J Zhou; Stefan Kane; Huda Safa; A Sparks; Lex W Doyle; A J McPhee; Tanya A C Nippita; Hossein H A Afzali; Rosalie Grivell; D Mackerras; E Knight; Simon Wood; Tim Green

doi:10.1136/bmjopen-2022-071359

Prenatal iodine supplementation and early childhood neurodevelopment: the PoppiE trial - study protocol for a multicentre randomised controlled trial

BMJ Open. 2023 May 10;13(5):e071359. doi: 10.1136/bmjopen-2022-071359.

Authors

Karen P Best^{1

2}, Jacqueline F Gould^{3

2}, Maria Makrides^{3

2}, Thomas Sullivan^{3

4}, Jeanie Cheong^{5

6}, Shao J Zhou⁷, Stefan Kane^{6

8}, Huda Safa^{9

10}, A Sparks¹¹, Lex W Doyle^{8

12}, A J McPhee³, Tanya A C Nippita^{13

14}, Hossein H A Afzali¹⁵, Rosalie Grivell¹⁶, D Mackerras¹⁷, E Knight^{3

4}, Simon Wood^{18

19}, Tim Green^{3

2}

Affiliations

¹ Women and Kids Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia karen.best@adelaide.edu.au.
² Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia.
³ Women and Kids Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
⁴ School of Public Health, The University of Adelaide, Adelaide, South Australia, Australia.
⁵ Newborn Services, Royal Women's Hospital, Parkville, Victoria, Australia.
⁶ Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Victoria, Australia.
⁷ School of Agriculture, Food & Wine, The University of Adelaide, Adelaide, South Australia, Australia.
⁸ Department of Maternal Fetal Medicine, Royal Women's Hospital, Parkville, Victoria, Australia.
⁹ School of Medicine, University of Queensland, Brisbane, Queensland, Australia.
¹⁰ Department of Obstetrics and Gynaecology, Mater Mothers' Hospital, Brisbane, Queensland, Australia.
¹¹ Department of Neonatology, Royal North Shore Hospital, St Leonards, New South Wales, Australia.
¹² Obstetrics and Gynaecology, Royal Women's Hospital, Parkville, Victoria, Australia.
¹³ Women and Babies, Kolling Institute of Medical Research, St Leonards, New South Wales, Australia.
¹⁴ Northern Clinical School, The University of Sydney, Sydney, New South Wales, Australia.
¹⁵ College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia.
¹⁶ Department of Obstetrics and Gynaecology, Flinders University, Adelaide, South Australia, Australia.
¹⁷ Menzies School of Health Research, Casuarina, Northern Territory, Australia.
¹⁸ Faculty of Land and Food Systems, University of British Columbia, Victoria, British Columbia, Canada.
¹⁹ Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia.

Abstract

Introduction: Observational studies suggest both low and high iodine intakes in pregnancy are associated with poorer neurodevelopmental outcomes in children. This raises concern that current universal iodine supplement recommendations for pregnant women in populations considered to be iodine sufficient may negatively impact child neurodevelopment. We aim to determine the effect of reducing iodine intake from supplements for women who have adequate iodine intake from food on the cognitive development of children at 24 months of age.

Methods and analysis: A multicentre, randomised, controlled, clinician, researcher and participant blinded trial with two parallel groups. Using a hybrid decentralised clinical trial model, 754 women (377 per group) less than 13 weeks' gestation with an iodine intake of ≥165 µg/day from food will be randomised to receive either a low iodine (20 µg/day) multivitamin and mineral supplement or an identical supplement containing 200) µg/day (amount commonly used in prenatal supplements in Australia), from enrolment until delivery. The primary outcome is the developmental quotient of infants at 24 months of age assessed with the Cognitive Scale of the Bayley Scales of Infant Development, fourth edition. Secondary outcomes include infant language and motor development; behavioural and emotional development; maternal and infant clinical outcomes and health service utilisation of children. Cognitive scores will be compared between groups using linear regression, with adjustment for location of enrolment and the treatment effect described as a mean difference with 95% CI.

Ethics and dissemination: Ethical approval has been granted from the Women's and Children's Health Network Research Ethics Committee (HREC/17/WCHN/187). The results of this trial will be presented at scientific conferences and published in peer-reviewed journals.

Trial registration number: NCT04586348.

Keywords: Developmental neurology & neurodisability; NUTRITION & DIETETICS; OBSTETRICS; PAEDIATRICS; PUBLIC HEALTH.

Publication types

Clinical Trial Protocol
Research Support, Non-U.S. Gov't

MeSH terms

Child
Child Health
Child, Preschool
Dietary Supplements
Female
Humans
Infant
Iodine* / therapeutic use
Multicenter Studies as Topic
Papaver*
Pregnancy
Randomized Controlled Trials as Topic
Vitamins
Women's Health

Substances

Iodine
Vitamins

Associated data

ClinicalTrials.gov/NCT04586348