1. Cervical pregnancy: It is a pregnancy in which the fertilized egg is implanted in the cervical canal, below the level of the histological endocervix, and grows and develops there. Cervical pregnancy is a very low incidence but dangerous type of ectopic pregnancy. Cervical pregnancy accounts for 1:1000- 95000 of pregnancies, with an incidence of <1% in ectopic pregnancies j. The morphological features of cervical pregnancy are infiltrative and destructive growth of the trophoblastic layer into the wall of the cervix to form placenta implantation, because the wall of the cervix contains only 15% muscular tissue, and the rest is fibrous connective tissue without contractile function, and when a cervical pregnancy occurs in a spontaneous abortion or a wrongly diagnosed curettage, it cannot rapidly expel the pregnancy because of the weak contraction force of the cervix. When cervical pregnancy occurs spontaneous abortion, misdiagnosed scraping, due to the weak contraction of the cervix, can not quickly discharge the pregnancy, open blood vessels do not atresia, bleeding. 2.Inter-myometrial pregnancy: a rare ectopic pregnancy, the pregnancy is located in the myometrial wall, surrounded by the myometrium, and the uterine cavity and fallopian tubes are not connected, accounting for about 1% of ectopic pregnancy. It is one of the more dangerous types of pregnancy. Mechanisms of intermuscular uterine pregnancy (1) endometrial defects: previous history of multiple uterine operations, history of uterine perforation, history of cesarean section, etc., the fertilized egg is implanted into the myometrium by the deficient endometrium, and continues to grow and develop there; (2) inflammation or deficiency of the plasma layer of the uterus: the fertilized egg is implanted into the myometrium by the umbilical end of the fallopian tube swimming and planting in the defective place of the uterine plasma membrane; (3) after artificial insemination, the embryo (3) Embryo implantation in the myometrium after artificial insemination with difficulty in the process of transfer; (4) Myometrial adenopathy: ectopic endometrium in the deeper part of the myometrium undergoes metaplasia due to the action of oestrogen and progesterone, which becomes a potential site for implantation of the fertilized egg. Diagnosis of uterine myometrial pregnancy There is no standardized criteria for the diagnosis of uterine myometrial pregnancy. before the 1990s, early diagnosis of uterine myometrial pregnancy was difficult, and it was often detected and diagnosed only when there was menopause, irregular vaginal bleeding, acute abdomen, or even shock during emergency surgery. since the 1990s, with the improvement of ultrasound technology, especially the application of vaginal ultrasound, more and more of the With the improvement of ultrasound technology since the 1990s, especially the application of vaginal ultrasound, more and more intermuscular pregnancies have been diagnosed and treated early. (1) Ultrasound: A gestational sac can be seen in the myometrium, especially in the scar of keloid uterus. The gestational sac is not related to endometrial echogenicity, and is associated with thinning or disappearance of the normal interstitial tissue of the myometrium. (2) Pathology ① Gross specimen: the lesion is located in the inter-myometrial wall, which is not connected with the uterine cavity and the opening of the fallopian tube; ② Microscopic examination: the lesion in the inter-myometrial wall can be seen as fresh or old chorionic tissue. (3) MRI: It has been reported abroad that MRI, as a non-invasive diagnostic tool, has become an important criterion for the diagnosis of intermural pregnancy. (3) Uterine scar site pregnancy: rarely reported, but in recent years, with the increase of cesarean section, the incidence of uterine scar site pregnancy is increasing year by year, and it is also a more dangerous type of abnormal pregnancy. The etiology of scar site pregnancy is not clear. Currently, most scholars believe that scar site pregnancy occurs due to implantation of a fertilized egg into the myometrium through a tiny fissure in the incisional scar. The formation of this tiny channel can be due to endometrial defects caused by previous cesarean section, manual extraction of the placenta, endometritis, or other uterine surgeries. The weakness of the myometrium here can cause uterine hemorrhage in the event of an enlarged gestational sac or abortion. In some cases, the incision thickness is as thin as 2mm, and the average thickness is only 4.3±3.12mm.The postoperative healing is composed of collagen fibrin bundles, and then myoblasts regenerate, accompanied by blood vessel regeneration.If the pregnant egg or placenta is implanted in this area, and if the gestational sac grows larger or the pregnancy is terminated, the blood sinus opens up when the placenta peels off, and the area is rich in blood, the patient bleeds the most, and the risk is huge. Due to the higher and prolonged bleeding, the rate of infection increases, making the bleeding more difficult to control. Therefore, early diagnosis and early treatment of pregnancy at uterine scar is more important.