Assessing iodine status and associated health effects in British women during pregnancy

Start date: 1 February 2016
End date: 31 May 2020
Funder: National Institute for Health and Care Research (NIHR)
Value: £1.5 million
Partners and collaborators: Bradford Hospitals NHS Trust; Born in Bradford; SCOPE study; University of Cambridge
Primary investigator: Dr Darren C Greenwood
Co-investigators: Professor Laura J Hardie, Professor Paul Stewart, Nigel Simpson
External co-investigators: Professor Janet Cade, School of Food Science and Nutrition University of Leeds, Prof John Wright, Bradford; Dagmar Waiblinger, Bradford; and supported by Prof Michael Zimmermann, Zurich; Prof Nisreen Alwan, Southampton; Prof Mark Mon-Williams, School of Pyschology; Professor Amanda Waterman; Professor Ramzi Ajjan, School of Medicine

Description

Iodine is a key micronutrient in the diet required for healthy development and metabolism. Iodine is important during pregnancy and breastfeeding when higher levels are required to support the developing child. Severe iodine deficiency is known to cause thyroid enlargement, disrupted thyroid hormone production, pregnancy complications, and impair child development.

A significant number of British women may have milder iodine deficiency but whether these levels have important health effects is not well understood. How levels of iodine and thyroid hormones change during pregnancy and breastfeeding and are affected by diet are currently not well described.

We will recruit 300 pregnant women from Bradford, West Yorkshire, identified at routine antenatal 12 week dating scans. Research nurses will administer a background questionnaire, food diary, collect a urine and blood sample, and assess the thyroid. Women will return to clinic at 26 and 36 weeks gestation, and at 6, 18 and 30 weeks post delivery (clinic or home visit) for repeat assessments. In the laboratory, we will analyse biological samples for iodine, creatinine and thyroid related hormones.

The data will allow us to identify key sources of iodine in the diet and investigate how levels vary during pregnancy and lactation, and associated changes in thyroid size and function. Under existing ethical approval arrangements we will also assess iodine levels in the Born in Bradford and SCOPE birth cohorts to link iodine levels to maternal health and child development.

The combined research is funded by the Department of Health and will allow us to estimate how many pregnant woman may have suboptimal levels of iodine, changes in iodine and thyroid function during pregnancy and breastfeeding, and whether levels of iodine are linked with health and developmental effects.

Impact

It is hoped that this research will inform updated World Health Organisation guidelines

Publications and outputs

Snart et al BMC Med 2020 - maternal iodine st_anonymous.pdf
Threapleton et al Paediatr Perinat Epidemiol_anonymous.pdf
Threapleton et al Nutrients 2021 - Pre & post_anonymous.pdf
Snart et al Nutrients 2019 - Maternal Iodine_anonymous.pdf
Cromie et al, BMC Pediatrics 2020 - Maternal_anonymous.pdf