1. Health education and guidance The principle of combining universal guidance and individualized guidance is followed to provide preconception health education and guidance to couples planning pregnancy. (2) Reasonable nutrition and control of body mass (weight) gain. (3) Folic acid supplementation of 0.4-0.8 mg/d or evidence-based medically proven multivitamin containing folic acid. Pregnant women with previous neural tube defects (NTD) should be supplemented with 4mg of folic acid daily. (4) Women with genetic, chronic and infectious diseases who are preparing for pregnancy should be evaluated and guided. (5) Use medication 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; avoid high-intensity work, high-noise environments and domestic violence. (8) Maintain mental health, relieve mental stress, and prevent the occurrence of psychological problems during pregnancy and after delivery. (9) Choose exercise reasonably. 2. Routine health care Assessment of pre-pregnancy risk factors: (1) Ask about the health status of the couple preparing for pregnancy. (2) Evaluate the history of previous chronic diseases, family and genetic history, and promptly inform those who are not suitable for pregnancy. (3) Detailed history of adverse pregnancy and childbirth. (4) Lifestyle, diet and nutrition, occupational status and work environment, exercise (labor), domestic violence, interpersonal relationships, etc. Physical examination: (1) Including measurement of blood pressure, body mass, and calculation of body mass index (BMI), BMI = body mass (kg)/height (m)2. (2) Routine gynecological examination. (3) Auxiliary examination Required items: (1) routine blood test; (2) routine urine test; (3) blood group (ABO and Rh); (4) liver function; (5) kidney function; (6) fasting glucose; (7) HBsAg; (8) plasma spirochete; (9) HIV screening; (10) cervical cytology (if not checked within 1 year). (1) Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus (TORCH) screening. (2) Cervicovaginal discharge examination (routine vaginal discharge, gonococcus, Chlamydia trachomatis). (3) Thyroid function test. (4) Thalassemia screening (Guangdong, Guangxi, Hainan, Hunan, Hubei, Sichuan, Chongqing, etc.) (5) 75g oral glucose tolerance test (OGTT; for high-risk women). (6) Blood lipid screening. (7) Gynecologic ultrasound examination. (8) Electrocardiogram. (9) Chest x-ray.