Objective To explore the relation between iodine nutritional status and thyroid function in pregnant women. Methods A total of 100 childbearing-age women were enrolled, including 31 euthyroid pregnant women (the euthyroid pregnant group), 36 pregnant women with thyroid dysfunction (the thyroid dysfunction pregnant group), and 33 euthyroid non⁃pregnant women (the euthyroid non⁃pregnant group), among which there were 12 gestational hypothyroidism, 7 simple gestational hypothyroxinemia, 3 gestational hyperthyroidism, and 14 gestational transient thyrotoxicosis (GTT) in the thyroid dysfunction pregnant group. Iodine nutritional status was compared between pregnant and non⁃pregnant women, and the occurrence status of thyroid disease was compared between pregnant women with different iodine nutritional status. Results (1) Women in both euthyroid pregnant and non⁃pregnant groups were overall iodine replete. However, euthyroid pregnant women obtained higher urinary iodine concentration (UIC) and UIC⁃to⁃urine creatinine (UIC/UCr) value compared with euthyroid non⁃pregnant women (P<0.05). (2) Among women in the thyroid dysfunction pregnant group, those with gestational hypothyroidism, simple gestational hypothyroxinemia, or GTT were overall iodine deficient. Compared with the euthyroid pregnant group, UIC was lower in women with simple gestational hypothyroxinemia and GTT, while UIC/UCr value decreased in gestational hypothyroidism and GTT women (P<0.05). (3) when pregnant women grouped based on UIC, the incidence rate of thyroid disease was higher in the iodine⁃deficient group than in the iodine⁃excess group (P<0.05). When pregnant women grouped based on UIC/UCr value, the incidence rate of thyroid disease was higher in the low⁃value group and the mid⁃value group than in the high⁃value group (P<0.05). Conclusion The incidence rate of thyroid disease in pregnant women with iodine excess decreases. A short⁃term excessive iodine nutritional state is beneficial for maintaining normal thyroid function during pregnancy.

无