In the fourth month of pregnancy, abortion can be performed in several ways: 1) Mifepristone combined with misoprostol. 2) Water bladder induction. 3) Intra-amniotic injection of Levano to induce abortion. The most commonly used method is intra-amniotic injection of levano to induce labor, which is performed by injecting 100mg of levano into the amniotic cavity under the guidance of ultrasound, causing fetal death and inducing uterine contractions. It usually begins to work 24 hours after the induction of labor and is effective within 72 hours. If it is ineffective for more than 72 hours, it should be repeated in the review of blood and liver function, etc., and can be performed again when there is no abnormality to induce labor with Levano.