The gestational sac is in a normal position on the anterior, posterior, left and right side walls of the uterus as well as on the fundus. If the gestational sac is at the horn of the uterus or close to the endocervix, it is considered an abnormal position. If the ectopic pregnancy can be diagnosed at the horn of the uterus, it can rupture suddenly, causing massive internal bleeding and endangering the life of the pregnant woman. Once the pregnancy is diagnosed in the interstitial horn of the uterus, surgery is performed as soon as possible for treatment. If it lays close to the endometrium, it may eventually form a hypoplastic placenta, creating the possibility of painless and massive bleeding. Therefore, it is important to pay high clinical attention to regular checkups, no heavy physical labor, and no intercourse during the entire pregnancy period.