1. Those with previous history of amenorrhea, scanty menstruation, heavy menstruation, infertility, infertility, habitual abortion, or adverse maternal history, such as early gestational embryonic arrest, intrauterine fetal death, fetal growth restriction, preterm delivery, and perinatal death. 2.Those with personal history and family history of thyroid disease. 3, goiter and thyroid surgery removal and I131 treatment history 4, found in the past increased serum TSH or positive thyroid autoantibodies 5, type 1 diabetes mellitus, or other autoimmune diseases personal history and family history 6, suggestive of hypothyroidism symptoms or clinical signs should be in the pre-pregnancy checkups and early pregnancy registration to do the thyroid function of the screening, found that the abnormalities of timely treatment.