Comparison of clinical effectiveness and subsequent fertility between hysteroscopic resection and vaginal repair in patients with cesarean scar defect: a prospective observational study

Objective To evaluate the clinical effectiveness and pregnancy rate after hysteroscopic resection (HR) and/or vaginal repair (VR) in patients with cesarean scar defect (CSD). Methods This prospective observational study enrolled 191 patients who received CSD surgery in the First affiliated hospital of Sun Yat-sen University between September 2019 to February 2022 (96 in HR and 95 in VR, respectively). Patient follow-up were performed three months after surgery in both groups by transvaginal ultrasound to confirm the presence of fluid in the niche, along with the resolution of prolonged menses at the same time. The primary outcome was the clinical effectiveness between HR and VR, identified by the resolution of prolonged menses. Results The rates of niche-fluid disappearance (70.1% vs 60.2%, P = 0.176) and prolonged menses resolution (74.8% vs 80.0%, P = 0.341) were comparable for HR and VR. A subgroup analysis for niche size revealed that HR provides patients with small niche a more favorable rate of menstrual resolution compared to VR (size of niche ≤ 15 mm 2 , a OR = 3.423, 95% confidence interval [CI] 1.073–10.918), but patients with large niche experience a lower rate of resolution compared to VR (size of niche > 25 mm 2 , a OR = 0.286, 95% CI 0.087- 0.938). During follow-up, 41 patients who wanted to conceive became pregnant. Kaplan–Meier estimates of the cumulative probability of pregnancy at 12 months and 24 months were 47.1% (95% CI: 34.5%, 58.8%) and 63.8% (95% CI: 52.5%, 72.9%), respectively. The median pregnancy time was 22 months (95% CI: 14.2, 29.8) after VR and 12 months (95% CI: 8.3, 15.7, Gehan-Breslow-Wilcoxon P = 0.021) after HR. Among patients with subsequent infertility, 31.6% achieved pregnancy by unassisted mode and 29.8% by IVF/ICSI. Moreover, among patients with previously failed IVF/ICSI treatment, 60% (12/20) obtained pregnancy, including 71.4% (10/14) after HR and 33.3% (2/6) after VR. Conclusions Hysteroscopic resection is as effective as vaginal repair at relieving symptoms of CSD-associated prolonged menses. Hysteroscopic resection is the modality of choice with an improvement in prolonged menses for small niche, while vaginal might be considered for a large niche. Furthermore, surgical intervention could improve the clinical pregnancy rate of CSD patients. All of these provide evidence for the individualized management of CSD.