The Urine Iodine to Creatinine as an Optimal Index of Iodine During Pregnancy in an Iodine Adequate Area in China

Iodine intake, as assessed by spot UI concentration in pregnant women, is inaccurate and increases the prevalence of iodine deficiency. The UI/Cr better reflects the 24-hour iodine excretion and circulating iodine levels during pregnancy and the postpartum period.