Iodine deficiency amongst pregnant women in South-West England
Knight, Bridget A.
Shields, Beverley M.
Pearce, Elizabeth N.
Braverman, Lewis E.
Wiley for Society for Endocrinology
Reason for embargo
Introduction: Iodine deficiency in pregnancy may impair foetal neurological development. The UK population is generally thought to be iodine sufficient; however recent studies have questioned this assumption. Our study aimed to explore the prevalence of iodine deficiency in a cohort of pregnant mothers from South-West England. Methods: Urine samples were obtained from 308 women participating in a study of breech presentation in late pregnancy. They had no known thyroid disease and a singleton pregnancy at 36-38 weeks gestation. Samples were analysed for urinary iodine concentrations (UIC). Baseline data included: age, parity, smoking status, ethnicity, BMI at booking, vitamin use, and a dietary questionnaire. There was no difference in median UIC between women with (n= 156) or without (n=152) a breech presentation (p=0.3), so subsequent analyses were carried out as a combined group. Results: Participants had a mean (SD) age 31(5) years, median (IQR) BMI 24.4(22.0, 28.3) kg/m2, 42% were primiparous, 10% smoked during pregnancy, 35% took iodine containing vitamins. 96% were Caucasian. Median (IQR) UIC was 88.0 (54.3, 157.5) µg/l, which is consistent with iodine deficiency by WHO criteria. A total of 224/308 (73%) of women had UIC values <150µg/l. Increasing milk intake was associated with higher UIC (p=0.021). There was no difference in median (IQR) UIC between those women who took iodine containing vitamins (n=108) and those who did not (n=200): 88(54, 168) vs 88(54, 150) µg/l, p=0.7. Conclusion: Iodine deficiency in pregnancy is common in South-West England. Measures to develop optimum prevention and treatment strategies are urgently needed.
This study was supported by the Small Grants Scheme of the Research & Development Department, Royal Devon and Exeter Hospital NHS Foundation Trust. BAK and BMS are funded by the National Institute for Health Research (NIHR) as core members of the NIHR Exeter Clinical Research Facility.
Accepted manuscript online: 2 November 2016