Risk factors associated with the failure of initial treatment for cesarean scar pregnancy.

Objective: To explore the factors related to cesarean scar pregnancy (CSP) treatment failure under different treatment strategies.

Methods: This is a cohort study that consecutively included 1637 patients with CSP. Characteristics including age, gravidity, parity, previous uterine curettages, time since the last cesarean section, gestational age, mean sac diameter, initial serum β-human chorionic gonadotropin, distance between gestational sac and serosal layer, CSP subtype, classification of blood flow abundance, fetal heartbeat presence, and intraoperative bleeding were recorded. Four strategies were performed separately on these patients. Binary logistic regression analysis was used to analyze the risk factors for initial treatment failure (ITF) under the different treatment strategies.

Results: The treatment methods failed in 75 CSP patients, and succeeded in 1298 patients. The analysis found that the presence of a fetal heartbeat was significantly associated with ITF of strategy 1, 2 and 4 (P < 0.05); sac diameter was associated with ITF of strategy 1 and 2 (P < 0.05); gestational age was associated with initial treatment failure of strategy 2 (P < 0.05).

Conclusion: There was no difference of the failure rate between ultrasound-guided evacuation and hysteroscopy-guided evacuation for CSP treatment with or without uterine artery embolization pretreatment. Sac diameter, fetal heartbeat presence, and gestational age were all associated with CSP initial treatment failure.