Eugenics means taking effective means to reduce the incidence of fetal defects. To achieve eugenics, a series of preparations need to be made before pregnancy, and after pregnancy, regular pregnancy tests should be conducted, and prenatal diagnosis should be carried out when necessary to reduce the incidence of fetal defects. If a woman intends to get pregnant, she needs to make a series of preparations in advance, such as quitting smoking and drinking six months in advance, taking folic acid three months in advance, having an ultrasound, and taking blood tests for eugenics and euthanasia, etc. If you are sure you are pregnant, you need to do a series of preparations during the first three months. If the pregnancy is confirmed, continue to take folic acid within three months of the early pregnancy. During pregnancy, be careful not to blindly use medication and avoid contact with toxic and harmful substances. If you have any symptoms of discomfort, you must use the medication under the guidance of your doctor. During pregnancy, you need to do all the pregnancy tests regularly, such as doing NT test, doing Down’s syndrome screening, non-invasive DNA test, and so on. If there is a high-risk situation, it may be necessary to do prenatal diagnosis, such as an amniocentesis.