[Clinical risk factors of cesarean scar pregnancies]

Objective: To explore the risk factors related to cesarean scar pregnancies (CSP). Methods: Among the patients during July 2016 to June 2021 in Peking University Third Hospital, 596 cases of CSP patients were included as study group, and 1 192 cases of intrauterine pregnancy(IUP) women with history of cesarean section(s) were chosen as control group through stratified sampling according to the civil year of previous cesarean section matched with CSP group. The correlation between the general situation of patients, the history of gravidity and parity, the history of surgeries in uterine cavity and the previous cesarean section and the occurrence of CSP was explored through multivariate logistic regression analysis. Results: The current age of 596 CSP patients was (34.6±4.4) years, and that of 1 192 IUP patients was (35.6±3.6) years (P<0.001). Multivariate logistic regression analysis showed that the following factors may increase the risk of CSP: age<35 years old (OR=2.306, 95%CI: 1.774-2.998), history of medical abortion (OR=1.629, 95%CI 1.102-2.407), pregnancy interval<2 years from the last cesarean section (OR=2.147, 95%CI: 1.237-3.726), pregnancy interval ≥8 years from the last cesarean section (OR=1.474, 95%CI: 1.110-1.957), history of surgeries in uterine cavity before the last cesarean section (OR=2.558, 95%CI: 1.809-3.615), history of surgeries in uterine cavity after the last cesarean section (OR=8.020, 95%CI: 5.966-10.781), previous cesarean delivery ≥2 times (OR=14.051, 95%CI: 9.699-20.356) and history of previous cesarean sections before labor (OR=2.683, 95%CI: 1.930-3.731)(all P<0.05). Conclusions: The occurrence of CSP is related to the age of patients, the history of medical abortion, pregnancy interval, the history of surgeries in uterine cavity and the previous cesarean section, among which previous cesarean delivery ≥2 times and history of surgeries in uterine cavity after the last cesarean section are the strongly associated risk factors.