The purpose of this study is to determine whether UACE(uterine artery chemo-embolization) followed by suction curettage under the guidance of ultrasonography or hysteroscopy can decrease complications in the treatment of Caesarean scar pregnancy (CSP).

CSP is a special form of ectopic implantation within a fibrous tissue surrounding the previous delivery caesarean scar. The probability of CSP is 1:1800 to 1:2,226 in all pregnancies, and 6.1% in ectopic pregnancy after cesarean delivery. It's a long-term complication after cesarean delivery with very serious consequences,such as uterine rupture and massive uterine bleeding.There are more than ten methods to treat CSP,however, no universal management guidelines have been established up to now.

Present methods for CSP treatment include:1)medical treatment,usually systemic or local methotrexate（MTX）;2）suction curettage;3)medicine combined with uterine curettage;3）surgical treatment（hysteroscopic,laparoscopic or vaginal surgery）;4) uterine artery embolization(UAE);5) The combined use of the above methods.

Moreover, the rupture of the CSP and heavy bleeding may still occur following medical treatment.Suction curettage and excision of the CSP are associated with profuse bleeding. Surgical treatment is less micro-traumatic than nonsurgical interventions. For CSP, UAE followed by suction curettage appears to have more advantage than systemic MTX treatment and may be a priority option.So some author suggests that curettage and systemic methotrexate therapy and embolization as single treatments should be avoided if possible,combination of them is more effective. Plenty of evidences suggested that UACE followed by suction curettage under the guidance of ultrasonography or hysteroscopy is a priority choice.

However,in our clinical practices,suction curettage of CSP is more difficult than usual induced abortion procedure of normal early pregnancy,because PCSD(previous cesarean scar defect)is very common in CSP.In random populations the incidence of PCSD is present in 24%-69% of women evaluated with transvaginal sonography. Scar defects were seen in 61% (66/108), 81% (35/43) and 100% (11/11) of the women who had undergone one, two and at least three Cesarean sections by the transvaginal ultrasound examination.

What is the incidence of complications of suction curettage combined with UACE for CSP treatment remains unknown.How to decrease the complications remains unknown too.So we designed this study.

At first,the investigators evaluated the sample size will be 108 at least through software PASS11, which actually was 144 finally.Then the CSP patients visited or transferred to Maternal and Child Health Hospital of Hubei Province(China) from June 2010 to June 2014 were recruited.Every patient was numbered in chronological sequence.Then participants were randomly assigned into three arms using a randomization table :Group A(Group hysteroscopic monitoring), Group B(Group ultrasonography monitoring),and Group C(Group no monitoring). Randomization was conducted via a system of sealed and numbered envelopes.

Everybody received UACE(uterine artery chemo-embolization) first. Superselective embolization of both uterine arteries was performed using gelatin sponge particles by two experienced radiologists. After the puncture of the right femoral artery, a 5-F Roberts uterine artery catheter was correctly placed in the bilateral uterine artery with the guidance of a 0.889-mm guidewire.A 50mg dose of MTX was infused bilaterally prior to the gelatin sponge particles selective embolism procedure. Postembolization angiography was performed to confirm that the occlusion of the vessels was complete. Within 24-48 h after UACE, women underwent suction curettage.The subatmospheric pressure was 200～500mmHg during suction curettage.

Women assigned to the Group A(Group hysteroscopic monitoring) received UACE followed by suction curettage under hysteroscopic monitoring.Before and after suction curettage, hysteroscopy was performed.If some residual tissues were found, suction curettage would be performed again to remove them.

Women assigned to the Group B(Group ultrasonography monitoring) received UACE followed by suction curettage under ultrasonography monitoring.The suction curettage procedure was performed under abdominal ultrasonography real- time monitoring.When there were nothing residual under ultrasonography,the procedure was completed.

Women assigned to the Group C(Group no monitoring) received UACE followed by suction curettage without monitoring.

All patients were observed during the hospitalization. Ages, weight,gravidity,parity,weeks of gestation, clinical manifestation of CSP,estimated blood loss, operation time,length of uterine cavity and PCSD(previous cesarean scar defect), and side effects(such as fever, nausea,and low abdominal pain) were recorded. The serum β-hCG level and renal, hepatic function, and complete blood count were measured before intervention. The size of the gestation sac or a heterogeneous mass was measured by transvaginal ultrasound at the same time.

The patients were followed up by measuring serum β-hCG level every week until the β-hCG level reverted to normal.All women were followed up 2 weeks and 2 months after operation, which included ultrasound examination, and clinical assessment (bleeding pattern and resumption of menses).

Theχ2 test were used for the analysis of enumeration data. The measurement data comparisons between groups were tested by ANOVA analysis. A probability value of<.05 was considered statistically significant.All data analyses were conducted with SPSS software (version17.0;SPSS,Inc,IBM,American).

Inclusion Criteria:

• pre-operative diagnosed as CSP;hemodynamic stability

Exclusion Criteria:

• acute PID(pelvic inflammatory disease) or vaginitis;shock;prior classical cesarean section;prior treatment with suction curettage or MTX