Identifying risk factors for cesarean scar pregnancy based on propensity score matching.

OBJECTIVE

The aim of this study was to investigate the possible risk factors for cesarean scar pregnancy (CSP).

METHODS

The CSP group comprised 499 women with CSP admitted to Taizhou Hospital of Zhejiang Province between December 2009 and December 2018, and the observation group comprised 499 women who delivered after a previous cesarean section, selected by propensity score matching. The demographic characteristics and pregnancy history of patients were collected. The independent sample t-test was performed to analyze the measurement data; the χ2 test or Fisher's exact test was performed to analyze the count data. Multivariate binary logistic regression analysis was performed for significant variables. The receiver operating characteristic (ROC) curve analysis was used to determine the optimum cutoff score for predicting risk factors for CSP.

RESULTS

After univariate analysis, binary logistic regression analysis revealed that the number of abortions, the proportion of previous cesarean sections performed in tertiary hospitals, the time since the previous cesarean section, the number of cesarean sections, and a trial of labor before a previous cesarean section were correlated with the occurrence of CSP (odds ratios (ORs) (95% confidence intervals [CIs]) of 1.420 (1.276-1.581), 0.631 (0.462-0.863), 0.950 (0.912-0.990), 8.482 (5.567-12.922), and 0.321 (0.212-0.487), respectively). The area under the ROC curve for the number of miscarriages, the number of cesarean sections, and time since a previous cesarean section was 0.625, 0.695, and 0.607, respectively. When the number of miscarriages, the number of cesarean sections and time since a previous cesarean section were 1.5, 1.5, and 4.5 years, Youden's index was the highest.

CONCLUSIONS

Multiple cesarean sections and multiple abortions are risk factors for CSP; a trial of labor before a previous cesarean section, a long interval between cesarean sections, and surgery in tertiary hospitals are protective factors for CSP.