Iodine deficiency amongst pregnant women in South-West England.
BACKGROUND
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, body mass index (BMI) at booking, prenatal 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, and 35% took iodine-containing vitamins. Ninety-six per cent 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 <150 μg/l. Increasing milk intake was associated with higher UIC (P = 0·02). 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.


CONCLUSIONS
Iodine deficiency in pregnancy is common in South-West England. Measures to develop optimum prevention and treatment strategies are urgently needed.
NIHR Exeter Clinical Research Facility, University of Exeter Medical School, University of Exeter, Exeter, UK.|Research & Development Department, Royal Devon and Exeter Hospital NHS Foundation Trust, Exeter, UK.
Bridget A
BA
Knight
NIHR Exeter Clinical Research Facility, University of Exeter Medical School, University of Exeter, Exeter, UK.
Beverley M
BM
Shields
Section of Endocrinology, Diabetes & Nutrition, Boston University School of Medicine, Boston, MA, USA.
Xuemei
X
He
Section of Endocrinology, Diabetes & Nutrition, Boston University School of Medicine, Boston, MA, USA.
Elizabeth N
EN
Pearce
Section of Endocrinology, Diabetes & Nutrition, Boston University School of Medicine, Boston, MA, USA.
Lewis E
LE
Braverman
Centre for Women's Health, Royal Devon and Exeter Hospital NHS Foundation Trust, Exeter, UK.
Rachel
R
Sturley
Department of Endocrinology, Royal Devon and Exeter Hospital NHS Foundation Trust, Exeter, UK.|University of Exeter Medical School, Exeter, UK.
Bijay
B
Vaidya
D000328:Adult; D001946:Breech Presentation; D015331:Cohort Studies; D019587:Dietary Supplements; D004739:England; D005260:Female; D005865:Gestational Age; D006801:Humans; D007455:Iodine / Q000172:deficiency* / Q000652:urine; D011247:Pregnancy; D015995:Prevalence; D055815:Young Adult
D007455:Iodine