Efficacy of caesarean scar defect repair in improving postmenstrual bleeding and factors associated with poor effect.

Caesarean scar defect (CSD) can cause postmenstrual bleeding. Defect repair is an effective technique to improve this symptom, but there are still a few patients getting little improvement. This retrospective study evaluates the efficacy of scar repair and explores the factors associated with poor effect. In total, 123 patients were involved in the final analysis. All of them complained about menstruation period >7 days due to postmenstrual bleeding. Before surgery, 87.8% of patients had a menstruation period more than 10 days and 20.3% had a period more than 15 days. After surgery, a normal menstruation period (< =7 days) was achieved in 46.3% (95%CI 37.3%-55.6%) of patients and a menstruation period lasting no more than 10 days was achieved in 74.8% (95%CI 66.2%-82.2%). Through multivariate logistic analysis, four factors were found dependently associated with poor effect (defined as menstruation period >10 days after surgery): repeated caesarean section (OR 9.75, 95%CI 2.30-41.36, 0.002) was a risk factor, while defect volume >600 mm3 (OR 0.14, 95%CI 0.03-0.56, 0.006), interval from caesarean section to symptom emerging >3 months (OR 0.25, 95%CI 0.07-0.94, 0.041) and straight or retroflexed uterus (OR 0.19, 95%CI 0.05-0.79, 0.022) were protective factors. Impact statement What is already known on this subject? Caesarean scar defect can cause postmenstrual bleeding. Defect repair can improve this symptom, but there are still a few patients getting little improvement after surgery. What do the results of this study add? Defect volume >600 mm3, interval from caesarean section to symptom emerging >3 months and straight or retroflexed uterus are protective factors of poor effect (defined as menstruation period >10 days after surgery), and repeated caesarean section is a risk factor. What are the implications of these findings for clinical practice and/or further research? These findings may help in counselling the patients and in medical decision. Further researches are needed to explore other factors associated with surgical effect and build prediction models.