Pregnant women with iodine deficiency at 6 months can choose iodine-containing medications, or iodine-containing foods such as kelp and nori for iodine supplementation. Adequate iodine intake during pregnancy is necessary for maternal thyroid hormone synthesis, for the maturation of the fetal central nervous system, and for the development of the nervous system in childhood. Iodine-deficient pregnant women are divided into a severe iodine deficiency group (urinary iodine value <50 μg/L), a moderate iodine deficiency group (urinary iodine value 50-99 μg/L) and a mild iodine deficiency group (urinary iodine value 100-150 μg/L). Those who clearly have iodine deficiency can take iodine supplementation medications such as iodized pregnant women multivitamins, potassium iodide and iodine-rich foods such as kelp, nori and seaweed to supplement iodine nutrition in iodine-deficient pregnant women. In the process of iodine supplementation, iodine levels need to be tested. It should be noted that hormone levels such as thyroxine and thyrotropin need to be monitored at the same time as iodine supplementation. The above iodine supplementation medications need to be administered under the supervision of a clinician.