The iodine excreted by our body is almost equal to the iodine intake under the condition of sufficient and stable iodine supply, so if the urine iodine value of the pregnant mother is low, it suggests that the iodine intake of the pregnant mother is insufficient. Iodine is a very important mineral needed by the human body. Insufficient iodine intake by pregnant mothers may lead to growth retardation, mental retardation and even cretinism in severe cases. Therefore, during pregnancy, we need to clarify whether pregnant mothers have iodine deficiency through urine iodine test. A single urine should be judged using the ratio of urinary iodine and urinary creatinine, while the test for urinary iodine alone should be performed using 24 hours of urine. If the urine iodine is below 150μg/L, it indicates that the pregnant mother’s iodine intake is insufficient. The Chinese Nutrition Society recommends supplementing with seaweed vegetables 1-2 times a week during pregnancy, which can be a good way to help pregnant mothers supplement their iodine intake.