The pre-pregnancy tests to be done for having a second child after cesarean section include vaginal ultrasound, blood tests such as routine blood tests, routine leukorrhea tests, and eugenics tests. 1. Vaginal ultrasound: after cesarean section belongs to the scarred uterus, if you want to give birth to a second child, you can have a vaginal ultrasound, mainly to monitor the thickness of the uterine incision scar, to check whether there is any lesion of the uterus, ovaries, fallopian tubes and so on. 2. Blood test: mainly to check with blood routine, liver and kidney function, infectious diseases without anemia, it is recommended that both husband and wife are examined before pregnancy. 3. Leukorrhea routine: mainly to see whether there is vaginal inflammation, or the existence of mycoplasma, chlamydia abnormalities, if abnormal, generally need to be thoroughly treated first, and then prepare for pregnancy. 4. Eugenics 8: Eugenics 8 tests include Toxoplasma gondii IgM antibody and IgG antibody, cytomegalovirus IgM antibody and IgG antibody, herpes simplex virus IgG and IgM antibody, rubella virus IgM rubella virus IgG antibody, through which you can check whether you are infected with a disease in your body. In addition, before preparing for the birth of a second child, it is also necessary to carry out tests according to individual circumstances, such as prenatal that is combined with other diseases, it is recommended to actively go to the hospital before pregnancy to consult the guidance of preparation for pregnancy, detailed consultation with a specialized doctor, and carry out the various tests under the advice of the doctor.