Iodine deficiency in a study population of pregnant women in Sweden

Abstract

Introduction. Iodine deficiency in utero may impair neurological development of the fetus. In Sweden, iodine nutrition is considered to be adequate in the general population. The aim of this study was to evaluate iodine nutrition during pregnancy in Sweden. Material and methods. In this cross-sectional study, the total study population (n = 459) consisted of two cohorts (Värmland County, n = 273, and Uppsala County, n = 186) of pregnant non-smoking women without pre-gestational diabetes mellitus or known thyroid disease before or during pregnancy. Spot urine samples were collected in the third trimester of pregnancy for median urinary iodine concentration (UIC) analysis. Results. The median UIC in the total study population was 98 μg/L (interquartile range 57-148 μg/L). Conclusions. According to WHO/UNICEF/IGN criteria, population-based median UIC during pregnancy should be 150-249 μg/L. Thus, our results indicate insufficient iodine status in the pregnant population of Sweden. There is an urgent need for further assessments in order to optimize iodine nutrition during pregnancy.