The Eugenics IV test is a fasting blood test to check for Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus infections in pregnant women to avoid miscarriage and fetal malformations, and is recommended during pregnancy preparation. The four eugenics tests are clinically important. For example, Toxoplasma gondii infection in women during pregnancy may cause miscarriage, premature birth, intrauterine fetal death, hydrocephalus and neurodevelopmental disorders in infants. Rubella virus infection may cause malformation, hepatosplenomegaly, neurodevelopmental disorders, congenital heart disease, etc. in newborns. Cytomegalovirus infection in pregnant women may cause fetal damage and eventually lead to intrauterine death of the fetus. Herpes simplex virus infection in pregnant women may induce miscarriage, premature birth, stillbirth, and malformation. Therefore, before preparing for pregnancy, women should actively cooperate with doctors for relevant pre-conception checkups for early detection, early treatment and early benefit. During the preparation period, pay attention to balanced nutrition, exercise properly, enhance physical fitness, maintain good living habits and a positive and optimistic psychological state to prepare the body for the conception of a healthy fetus.