Vaccination usually does not cause the embryo to stop developing because most of the vaccines are live attenuated and inactivated vaccines, etc., which usually do not cause fetal arrest in people with general health conditions. For people with allergies, it may cause an overreaction of the body’s immune system, leading to fetal arrest. Live attenuated and inactivated vaccines actually weaken or remove the pathogenicity of the viruses in them, but only retain their antigenicity, which can stimulate the body to produce specific antibodies, so that the body can obtain immunity, and usually do not cause fetal arrest. For most people, vaccines do not cause fetal arrest, but for those who are susceptible to allergies, vaccines may cause fetal arrest. However, since some vaccines have been used in the clinic for a relatively short period of time, it is not yet possible to adequately determine the effects of vaccines on the immune system of pregnant women and on the development of the embryo, so it is recommended that pregnant women avoid vaccines as much as possible during pregnancy.