Iodine status of pregnant women with obesity from inner city populations in the United Kingdom

Background/objectives Iodine is essential for foetal neurodevelopment and growth. Requirements increase in pregnancy to support increased thyroid hormone synthesis for maternal and foetal requirements, and for foetal transfer. Iodine deficiency in pregnancy is widely reported, and obesity has been associated with sub-optimal thyroid function. We evaluated iodine status and its relation with birthweight in a secondary analysis of pregnant women with obesity from multi-ethnic inner-city settings who participated in the UK Pregnancies Better Eating and Activity trial (UPBEAT). Subjects/methods Iodine and creatinine concentrations were evaluated in spot urine samples in the second (15.sup.+0-18.sup.+6 weeks, n = 954) trimester of pregnancy. We assessed iodine status as urinary iodine concentration (UIC) and urinary iodine-to-creatinine ratio (UI/Cr) and applied WHO/UNICEF/IGN population threshold of median UIC > 150 [micro]g/L for iodine sufficiency. Relationships between iodine status and birthweight were determined using linear and logistic regression with appropriate adjustment, including for maternal BMI and gestational age. Results Median (IQR) UIC and UI/Cr in the second trimester of pregnancy were 147 [micro]g/L (99-257) and 97 [micro]g/g (59-165), respectively. An UI/Cr 150 [micro]g/g, there was a trend for women with UI/Cr Conclusions Iodine status of pregnant women with obesity from this cohort of UK women was suboptimal. Lower iodine status was associated with lower birthweight.
Author(s): Jessica Farebrother [sup.1] [sup.2] , Kathryn V. Dalrymple [sup.1] , Sara L. White [sup.1] , Carolyn Gill [sup.1] , Anna Brockbank [sup.1] , John H. Lazarus [sup.3] , Keith [...]