Preconception health care is to prevent the occurrence of birth defects by assessing and improving the health status of couples planning to conceive, reducing and eliminating risk factors that lead to adverse pregnancy outcomes such as birth defects, and carrying out the following examination programs in accordance with national norms: 1. Routine health care: mainly includes assessment of preconception high-risk factors and physical examination. A comprehensive physical examination, including cardiopulmonary auscultation, measurement of blood pressure, weight and calculation of body mass index, and routine gynecological examination; 2. The mandatory checkups are for every pregnant woman, and the backup checkups are for individualized checkups only. The mandatory items include blood routine, urine routine, blood type, liver function, kidney function, fasting blood sugar, surface antigen, syphilis and HIV. As a backup, if a woman has not had a cervical cancer screening within one year, she should have a cervical exfoliation cytology, viral infection, vaginal discharge examination, including routine vaginal discharge examination, as well as gonococcal and Chlamydia trachomatis tests; thyroid function test and diabetes screening. For high-risk women, lipid level testing, gynecological ultrasound, electrocardiogram, and chest X-ray are required; 3. Some targeted tests are done for individualized women.