Long-term gynecologic, reproductive, and ultrasound outcomes after hysteroscopic resection versus dilation and evacuation for cesarean scar pregnancy: a secondary analysis of a randomized clinical trial.

INTRODUCTION: Cesarean scar pregnancy (CSP) is a rare form of ectopic pregnancy in which the gestational sac implants within the myometrial defect of a previous cesarean section. We previously conducted a randomized clinical trial (RCT) comparing hysteroscopic resection versus ultrasound-guided dilation and evacuation (D&E), both preceded by systemic methotrexate, for the treatment of CSP with positive embryonic heart activity. That trial demonstrated a higher success rate in women undergoing hysteroscopic resection. Beyond immediate treatment success, women treated for CSP may experience chronic gynecologic symptoms and impaired fertility. OBJECTIVE: To evaluate long-term gynecologic symptoms and reproductive and ultrasound outcomes in women previously enrolled in the parent RCT. METHODS: This is a secondary analysis with long-term follow-up of a RCT comparing hysteroscopic resection versus ultrasound-guided D&E for the treatment of CSP. Women with singleton CSP and positive embryonic cardiac activity randomized between February 2020 and August 2022 were eligible. Participants were contacted 4-6 years after treatment (January-February 2026) and invited to a single follow-up visit including structured assessment of gynecologic symptoms, reproductive history, and transvaginal ultrasound evaluation of cesarean scar characteristics, including the presence of a uterine niche. Outcomes included post-treatment gynecologic symptoms, subsequent fertility and pregnancy outcomes, and ultrasound-assessed scar features. Analyses were conducted according to the intention-to-treat principle, with effect estimates reported as relative risks (RR) with 95% confidence intervals (CI). RESULTS: Of the 54 women originally randomized, 3 had undergone hysterectomy at the time of the parent trial, leaving 51 women eligible for long-term follow-up. Of these, 26 (51%) were successfully contacted and included in the long-term follow-up analysis, with a median follow-up of 4.59 years. Fourteen women also underwent follow-up transvaginal ultrasound assessment. Dysmenorrhea was less frequent in the hysteroscopic resection group compared with the ultrasound-guided D&E group (6.3% vs 50%; RR 0.13, 95% CI 0.02 to 0.92). No clear differences were observed in other gynecologic outcomes. Among the 9 women who attempted conception, 7 of 8 women in the hysteroscopic resection group and 1 of 1 woman in the D&E group achieved a subsequent pregnancy. The only subsequent pregnancy in the D&E group was a recurrent CSP. On ultrasound follow-up, the frequency of uterine niche was similar between groups (63.6% vs 66.7%; RR 0.95, 95% CI 0.38 to 2.39). Niche depth was greater after hysteroscopic resection (MD 1.10 mm, 95% CI 0.04 to 2.16), and residual myometrial thickness was thinner compared with D&E (MD -1.30 mm, 95% CI -2.02 to -0.58). CONCLUSION: In this secondary analysis with medium- to long-term follow-up, hysteroscopic resection for CSP was associated with a lower rate of dysmenorrhea compared with ultrasound-guided dilation and evacuation, while no clear differences were observed in other gynecologic or reproductive outcomes. The frequency of uterine niche was similar between groups, although differences in niche depth and residual myometrial thickness were observed. TRIAL REGISTRATION: Clinicaltrials.gov NCT04205292.