The uterus is like an inverted pear and the uterine cavity is like an inverted triangle. The bottom of the triangle is the bottom of the uterus, the tips on both sides of the triangle are the opening of the fallopian tubes, called the horn of the uterine cavity, and the tip below the triangle is the cervical opening. In a normal pregnancy, the embryo is attached to the center of the triangle. If the embryo attaches near the tip of the opening of the fallopian tube, it is called a horn pregnancy, and if it attaches near the lower part of the cervix, it is called a cervical pregnancy. Although both of these pregnancies are inside the uterine cavity and are not ectopic, they are still technically ectopic pregnancies because they deviate from the optimal embryo implantation site. Therefore, they should be highly valued, detected as early as possible, closely observed and correctly treated. 1. Symptoms: Early on, there are no symptoms and it is not easy to be detected. As the embryo develops and grows, the space at the horn of the uterus is limited, the uterine wall becomes bookish and the tension is large, so abdominal pain may appear. The placenta is narrowly attached, which can lead to partial abruption of the fetal slate and vaginal bleeding, or even miscarriage. When the embryo reaches 8-12 weeks of development, the uterine horn becomes more tense and the uterine wall is more bookish, which may lead to rupture of the uterine horn and hemorrhage. As the uterine artery and the ovarian tube artery are crossed and anastomosed at the uterine horn, there is abundant blood flow and once the rupture is violent, it can lead to hemorrhagic shock and death if not treated in time. A few patients can develop to full-term pregnancy and delivery, but it is often prone to placental adhesion retention. 2, diagnosis: mainly rely on ultrasound diagnosis, if necessary, color ultrasound more clear and accurate. The diagnosis can be confirmed by laparoscopy, which shows that the horn of the uterus on the affected side is enlarged and purplish in color, with many blood vessels on the surface. The affected side of the garden ligament is displaced laterally. 3, treatment: asymptomatic people can expect therapy, close observation, expect the embryo to the uterine cavity growth, and normal delivery. During this period, avoid strenuous activities and monitor regularly with ultrasound under the guidance of the doctor. Aspiration is performed under ultrasound monitoring. If the embryo is large and the uterus is thin, laparoscopic aspiration or incisional aspiration can be performed. In case of rupture and hemorrhage, laparoscopic hemostasis repair or hysterectomy can be performed immediately. Emergency laparotomy should be performed if the condition is not available.