目的:探讨用尿碘浓度(UIC)/尿肌酐(UCr)比值评价妊娠早期妇女碘营养状况的参考区间。方法:在5 609名甲状腺功能正常、甲状腺自身抗体阴性、无影响甲状腺功能的疾病和药物应用史的妊娠早期妇女中，确定UIC/UCr比值的参考区间，然后在7 514名妊娠早期妇女中验证该参考区间的可靠性。结果:以UIC/UCr比值在75～149 μg/g作为参考区间，在参考区间内，甲状腺球蛋白抗体(TgAb)、甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白(Tg)的水平均较低，整体呈现近似U型分布。甲状腺功能异常患病率、抗体阳性率和Tg>40 μg/L的比例在参考区间内最低，在该区间两侧则较高。结论:碘充足地区妊娠早期妇女UIC/UCr比值的参考区间为75～149 μg/g，是合理的碘营养状态。“,”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.