All pregnant women are required to undergo preconception testing when they intend to become pregnant, regardless of whether they have had normal children in the past. Pregnant women without special medical history generally need to be checked for the following items: 1. thyroid function check: because abnormal thyroid function can directly affect the intellectual development of children; 2. infectious diseases: hepatitis B, syphilis, AIDS, hepatitis C and other infectious diseases, if patients with infectious diseases need to be checked, while those without infectious diseases should be screened; 3. eugenics five items: including rubella virus, cytomegalovirus, herpes virus The infection of these viruses is likely to cause fetal malformation; 4, screening for thalassemia: not all people must be checked, but the high incidence areas, including Hainan, Guangdong, Guangxi, Fujian and other coastal areas, Sichuan, Hubei is also a high incidence areas, people in these high incidence areas should be screened for thalassemia; 5, screening for cervical cancer: it is recommended that those who have not done this test within one year of pregnancy The screening of HPV (human papillomavirus) and TCT (liquid-based thin layer cell test) is recommended for those who have not had this test within one year of pregnancy; 6.