Systematic evaluation of the efficacy of treatments for cesarean scar pregnancy.

Study objective: Cesarean scar pregnancy (CSP) is a type of ectopic pregnancy associated with severe complications, including significant hemorrhage, the potential need for hysterectomy, and life-threatening risks. Currently, two classification methods exist for CSP: Vial (type I^a and II^a) and Chinese Expert's Consensus (type I^b, type II^b, and type III^b). However, these methods have limitations in guiding the selection of appropriate treatment plans for CSP. The purpose of this study was to systematically evaluate the effectiveness of various treatments for CSP within our clinic.

Method: Our study included 906 patients with CSP from January 2013 to December 2018. The chi-squared test and logistic analysis were used to compare the clinical characteristics. The median and interquartile range (IQR) was calculated. We also analyzed whether preoperative application of methotrexate (MTX) could improve surgical outcomes and the relevant characteristics of misdiagnosed CSP patients.

Results: There was a significant difference in gestational age, gestational sac diameter, gestational sac width, gestational sac area, remnant myometrial thickness, vaginal bleeding and preoperative hemoglobin levels (p < 0.001) but not in the incidence of residual tissue (p = 0.053). The other factors (intraoperative blood loss, hemoglobin decline, first hemoglobin after operation, total hospital stay, hospital stay after operation, transfusion and duration of catheter drain) were significantly different (p < 0.001). For type I^a and type I^b CSP, 39.3% and 40.2% of patients were treated with dilatation and curettage (D&E) under ultrasound, respectively. For type II^a and type III^b CSP, 29.9% and 62.7% of patients were treated with laparotomy, respectively. There were no differences in surgical methods, residual tissue and reoperation between the MTX and non-MTX groups (p = 0.20), but liver damage, hospital stay and pain perception were more remarkable in the MTX group. It is noteworthy that 14% of the patients were misdiagnosed with an intrauterine pregnancy. The incidence of misdiagnosis in type II^a CSP patients was higher than that in type I^a CSP patients (p < 0.001).

Conclusion: For type I CSP patients, D&E under ultrasound or D&E under hysteroscopy should be recommended. For type III^b CSP patients, operative resection should be used. It is currently difficult to choose the appropriate treatment methods for type II^a or type II^b CSP patients.