Cesarean uterine scar pregnancy (CSP) is a rare form of ectopic pregnancy, a special form of myometrial pregnancy, different from isthmus pregnancy, which is an intrauterine pregnancy. Early diagnosis and proper and timely management are advocated to effectively reduce complications and successfully preserve fertility; delayed diagnosis and improper management can lead to hemorrhage/uterine rupture/total hysterectomy or even life-threatening. In addition to the general clinical manifestations of early pregnancy, CSP may have the following manifestations: (1) irregular vaginal bleeding in early pregnancy and or with vague lower abdominal pain; (2) heavy/recurrent bleeding during or after abortion or curettage without preoperative diagnosis; (3) bleeding that occurs after a medication abortion and heavy bleeding at the time of clearing the uterus for diagnosed incomplete abortion; (4) enlarged, soft uterus with dilated or inconspicuous isthmus; no cervical abnormalities or blockage of blood clots. Early clinical diagnosis is difficult and relies on ultrasound and other ancillary tests. The main ultrasound diagnostic criteria for CSP are: (1) no gestational sac is detected in the uterine cavity or cervical canal; (2) the gestational sac or mixed mass is located in the anterior wall of the isthmus at the level of the internal cervical os or at the scar of a previous cesarean section; (3) the gestational sac or mass is separated from the bladder, with thinning or interruption of the continuity of the anterior myometrium of the lower uterine segment; (4) color Doppler flow imaging detects a clear circumferential blood flow signal around the trophoblastic layer of the gestational sac (5) no masses are detected in the adnexal region and there is no free fluid in the rectal uterine trap (except for csp rupture). CSP should be differentially diagnosed from isthmus pregnancy, cervical pregnancy, trophoblastic disease and some other diseases such as miscarriage, uterine fibroid degeneration, and myometrial injury. The treatment of CSP is becoming standardized, improved and individualized, and corresponding norms and guidelines have been developed in China. The consensus view is to emphasize early diagnosis of CSP and timely intervention to terminate pregnancy once diagnosed. The main treatment methods are pharmacological, embolization and surgical treatment, which include direct curettage, hysteroscopic surgery, laparoscopic surgery, open or transvaginal pregnancy lesion removal and hysterectomy. The latter is only used in cases where other treatment modalities have failed or when the patient is old and combined with other gynecological disorders. Nowadays, combined treatment such as MTX drug therapy ± hysterectomy; uterine artery embolization (UAE) ± MTX + hysterectomy, combined hysterolaparoscopic surgery, etc. is mostly used. The decision of the treatment plan is based on the following points: (1) the severity of the patient’s symptoms; (2) the size, location, and relationship between the sac or mass and the uterus; (3) the importance of defining the thickness between the sac or mass and the bladder wall; (4) the CDFI status and the blood HCG level; (5) the treatment experience and equipment and technology. It is crucial to choose a safe, minimally invasive, short hospital stay and low cost treatment for CSP. Vial et al. (2000) suggested that there are two different forms of CSP, type I, in which the gestational sac grows into the uterine cavity with the possibility of continuing the pregnancy, but complications such as uterine rupture and severe bleeding often occur in the middle and late stages. In type II, the chorionic villi are deeply implanted in the scar and bleeding or even uterine rupture occurs in early pregnancy, which is extremely dangerous. This typology is not easy to grasp clinically and has limited clinical guidance. the first symposium on scar pregnancy was held on August 7-9, 2015 by the Chinese Medical Association Family Planning Branch, in anticipation of the release of new guidelines that will guide clinical treatment choices. Prof. Cui Baoxia retrospectively analyzed the medical records of 83 patients with primary CSP at Qilu Hospital of Shandong University, with no significant differences in patient admissions, and compared the intraoperative bleeding, length of stay, total hospitalization cost, and rehospitalization rate between the drug pretreatment (mainly MTX) + surgery group and the direct surgery group (ultrasound-supervised uterine clearance, hysteroscopic surgery, laparoscopic surgery, or combined surgery). The intraoperative bleeding volume increased, but it was still within the acceptable range, and only a few people needed blood transfusion. The typing of CSP and the choice of treatment modality in the current clinical practice of Qilu Hospital of Shandong University are for reference only. Type I: thinest part of the uterine pulpy muscle layer at the scar >7.5px; regardless of the condition of the gestational sac, clearance under ultrasound surveillance + hysteroscopy (if residual, then electrodesiccation, later the same). Type II: thinest part of the uterine plasma layer at the scar < 7.5px but >2.5px, the sac or mass is not protruding or slightly convex towards the bladder. If the mass is less than 75px, the uterus is cleared under ultrasound surveillance + hysteroscopy; if the mass is greater than 75px, the uterus is cleared under laparoscopic surveillance and the scar is opened to repair the defect if necessary. Type III: myometrium at the scar < 2.5px or discontinuous, with the mass clearly convex to the bladder. If the mass is less than 150 px, direct combined utero-abdominal or transvaginal surgery is indicated; if the mass is more than 150 px, with abundant local blood flow, open surgery is considered. Therefore, the important reference for treatment is the myometrium of the scar, the size and convexity of the gestational sac or mass, and the success rate of surgery is high and bleeding is low if the myometrium is continuous. Aggressive surgical treatment is more recommended for those with live embryos, as medication is long and has a lower chance of success. Embolization is used only in exceptional cases or as an alternative to surgical treatment in emergency situations and may not be used routinely as a preoperative procedure. To reduce intraoperative bleeding in CSP, it is crucial to achieve complete abortion in a short period of time, so paracervical injection of diluted posterior pituitary hormone is recommended, direct injection into the vessels should be avoided, monitoring should be reinforced and attention should be paid to its side effects. The prevention of CSP is particularly important because the defect of scar healing can persist for a long time and CSP can occur at any reproductive age. Reducing the rate of cesarean delivery, improving the technique of closing the uterine incision, reducing the number of uterine operations and implementing effective contraceptive methods can effectively reduce the occurrence of CSP. Finally, we hope to find the best treatment plan for different types of CSP through a multicenter clinical study and to improve the appropriate treatment guidelines for CSP in China. Through the collaboration of multidisciplinary departments such as obstetrics, gynecology, birth control, ultrasound and interventional medicine, we aim to reduce the occurrence of CSP, improve the diagnosis of CSP and standardize the treatment of CSP.