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

BACKGROUND: Cesarean scar pregnancy 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 trial comparing hysteroscopic resection with ultrasound-guided dilation and evacuation, both preceded by systemic methotrexate, for the treatment of cesarean scar pregnancy with positive embryonic heart activity. That trial demonstrated a higher success rate in women undergoing hysteroscopic resection. Beyond immediate treatment success, women treated for cesarean scar pregnancy may experience chronic gynecologic symptoms and impaired fertility.

OBJECTIVE: This study evaluates long-term gynecologic symptoms and reproductive and ultrasound outcomes in women who were previously enrolled in the parent randomized trial.

STUDY DESIGN: This is a secondary analysis with long-term follow-up of a randomized trial comparing hysteroscopic resection vs ultrasound-guided dilation and evacuation for the treatment of cesarean scar pregnancy. Women with singleton cesarean scar pregnancy and positive embryonic cardiac activity who were randomized between February 2020 and August 2022 were eligible. Participants were contacted 4 to 6 years after treatment (January-February 2026) and invited to a single follow-up visit, which included a structured assessment of gynecologic symptoms, reproductive history, and transvaginal ultrasound evaluation of cesarean scar characteristics, including the presence of a uterine niche. Outcomes included posttreatment 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 with 95% confidence intervals.

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. Out of 26 women, 14 also underwent follow-up transvaginal ultrasound assessment. Dysmenorrhea was less frequent in the hysteroscopic resection group than in the ultrasound-guided dilation and evacuation group (6.3% vs 50.0%) (relative risk, 0.13 [95% confidence interval, 0.02-0.92]). No clear differences were observed in other gynecologic outcomes. Among the 9 women who attempted conception, 7 of the 8 women in the hysteroscopic resection group and 1 woman in the dilation and evacuation group achieved a subsequent pregnancy. The only subsequent pregnancy in the dilation and evacuation group was a recurrent cesarean scar pregnancy. On ultrasound follow-up, the frequency of uterine niche was similar between the groups (63.6% vs 66.7%) (relative risk, 0.95 [95% confidence interval, 0.38-2.39]). Niche depth was greater after hysteroscopic resection (mean difference, 1.10 mm [95% confidence interval, 0.04-2.16]), and residual myometrial thickness was thinner than after dilation and evacuation (mean difference, -1.30 mm [95% confidence interval, -2.02 to -0.58]).

CONCLUSION: In this secondary analysis with medium- to long-term follow-up, hysteroscopic resection for cesarean scar pregnancy was associated with a lower rate of dysmenorrhea compared with ultrasound-guided dilation and evacuation, and no clear differences were observed in other gynecologic or reproductive outcomes. Although the frequency of uterine niche was similar between the groups, differences in niche depth and residual myometrial thickness were observed.