I. Health education and guidance Follow the principle of combining universal guidance and personalized guidance, the main contents include: (1) Prepared and planned pregnancy, avoiding pregnancy at advanced age. (2) Reasonable nutrition and control of body mass (weight) gain. (3) Supplementation with folic acid 0.4-0.8 mg/d, or evidence-based medically proven multivitamin containing folic acid. Pregnant women with previous neural tube defects (NTD) require folic acid supplementation of 4mg/d. (4) Women with genetic, chronic and infectious diseases who are preparing for pregnancy should be evaluated and guided. (5) Use medications rationally and avoid using drugs that may affect normal fetal development. (6) Avoid exposure to toxic and harmful substances in the living and occupational environment (such as radiation, high temperature, lead, mercury, benzene, arsenic, pesticides, etc.) and avoid close contact with pets. (7) Change bad habits (such as smoking, alcoholism, drug abuse, etc.) and lifestyles; (8) Maintain mental health, relieve mental stress, and prevent the occurrence of psychological problems during pregnancy and after delivery. (9) Reasonable choice of exercise. (2) Routine health care 1. Assessment of pre-pregnancy risk factors: (1) Ask about the health status of the couple preparing for pregnancy. (2) Assess previous history of chronic diseases, family and genetic history, those who are not easily pregnant should be informed in time. (3) Detailed history of adverse pregnancy and delivery. (4) Lifestyle, diet and nutrition, occupational status and work environment, exercise (labor) situation, domestic violence, interpersonal relationships, etc. 2. Physical examination: (1) Including measurement of blood pressure and body mass, calculation of body mass index (BMI), BMI = body mass (kg)/height O. (2) Routine gynecological examination. (3) Auxiliary examination 1. Mandatory items: (1) routine blood test; (2) routine urine test; (3) blood group (ABO and Rh); (4) liver function; (5) kidney function (6) fasting blood sugar (7) HbsAg (8) syphilis spirochete (9) HIV screening (10) cervical cytology (for those who have not been examined within 1 year) 2. Herpes simplex virus (TORCH) screening. (2) Cervicovaginal discharge test (routine vaginal discharge, gonococcus, Chlamydia trachomatis) (3) Thyroid function test (4) Thalassemia screening (5) 75g oral glucose tolerance test (OGTT: for high-risk women) (6) Lipid test (7) Gynecological ultrasound (8) Electrocardiogram (9) Chest X-ray Note: Do not neglect oral examination, any gum problem should be be treated before pregnancy.