IVF twin fetuses are reduced at 8-11 weeks of pregnancy, and the shorter the pregnancy, the higher the success rate when reducing the fetus. If the pregnant woman is a woman of advanced maternal age, has a history of spontaneous abortion, or delivers a fetus with congenital diseases, it is recommended that the reduction be considered after the middle of pregnancy, and when the reduction is carried out in the middle of pregnancy, it can be retained on the basis of merit, and if the development of the two fetuses after the middle of pregnancy is relatively normal, and the mother can tolerate it, it can be considered that both fetuses can be retained, and if the fetus or the mother cannot tolerate it, it is recommended that the fetus which develops better be selected and retained. Retention. When pregnancy is carried out through IVF, the chance of twin fetuses is relatively high, and the reduction of pregnancy should be determined according to the basic conditions of the pregnant woman, and if it is the first pregnancy, it is recommended to choose to carry out the reduction of pregnancy in the early stage of pregnancy in order to ensure the smooth progress of the pregnancy.