Establishment and application of reference interval for urinary iodine concentration/urinary creatinine ratio in early pregnancy / 中华内分泌代谢杂志

ABSTRACT

Objective:To explore the reference interval of urinary iodine concentration(UIC)/urinary creatinine(UCr) ratio evaluating the iodine nutritional status in early pregnancy women.Methods:A reference interval of UIC/UCr ratio was determined among 5 609 early pregnant women with normal thyroid function, negative thyroid autoantibodies, and no history of diseases or taking drug that may affect thyroid function. Then we verified the reliability of this reference interval in a group of 7 514 women in early pregnancy.Results:We determined the UIC/UCr ratio of 75-149 μg/g as the reference interval. In the reference interval, thyroglobulin antibody(TgAb), thyroid peroxidase antibody(TPOAb), and thyroglobulin(Tg) were all at lower levels, and the overall distributions were approximately U-shaped. The prevalence of thyroid dysfunction, the positive rates of antibodies and the proportion of Tg>40 μg/L were the lowest within the reference interval, while higher on both sides of the interval.Conclusion:The reasonable reference interval of the UIC/UCr ratio in iodine-sufficient regions is 75-149 μg/g in early pregnerty women.