The incidence of multifetal pregnancies has risen owing to wide application of assisted reproductive techniques. However, the risk of multifetal pregnancies has recently decreased by limiting the number of embryos to be transferred or by canceling ovarian hyper-response cycle. Multifetal pregnancies increase maternal and perinatal risk. Thus, selective fetal reduction in the second trimester is necessary in some cases. Fetal reduction is usually reserved for two fetuses. The success rate of pregnancy after birth reduction decreases with the increase in the number of initial fetuses. The determination of chorionicity is critical for perinatal management. According to the different chorionicity, surgical methods the drug injection or umbilical vascular occlusion are selected for the mid-term pregnancy reduction. Assisted reproductive technology also increases the rate of monochorionic diamniotic twin pregnancies. Abnormal vascular anastomosis and unequal placental sharing may lead to adverse pregnancy outcomes in monochorionic diamniotic twin pregnancies. And that is complex twins. Fetal reduction in multiple pregnancy can benefit health of pregnant women and remained fetuses. However, pregnancy loss may occur in a small number of pregnancies. So, we should get the indications for fetal reduction right and respect the informed choices of the pregnant women and their families.