The effects of iodine deficiency on the fetus may include cretinism and others, which should be analyzed according to the actual situation. 1. Cretinism: severe iodine deficiency in pregnant women may lead to cretinism in newborns, and children with cretinism will suffer from mental retardation and growth retardation, lagging behind normal children of the same age. The incidence of cretinism caused by iodine deficiency will be significantly reduced if the patient takes appropriate iodine supplementation measures. 2. Others: When pregnant women suffer from mild iodine deficiency, the effect on the fetus is not clear. Hypothyroidism or subclinical hypothyroidism caused by iodine deficiency may affect the future growth and development, intelligence and social adaptability of the fetus. Therefore, patients should be aware of iodine deficiency and treat it promptly once it is detected so as not to affect the health of the fetus.