Reproductive Outcomes Following High-Intensity Focused Ultrasound Treatment for Cesarean Scar Pregnancy

Cesarean scar pregnancy (CSP) is a rare but potentially life-threatening form of ectopic pregnancy associated with uterine rupture and severe hemorrhage. Optimizing fertility-preserving treatment strategies remains a critical clinical challenge. To investigate the reproductive outcomes and associated risk factors in patients with CSP after conservative surgery utilizing High-Intensity Focused Ultrasound (HIFU).

In this retrospective cohort study (July 2017-June 2020), 337 CSP patients were stratified into HIFU group (n=210) or the non-HIFU group (n=127). Multivariate logistic regression identified predictors of re-pregnancy and recurrent cesarean scar pregnancy (RCSP).

The re-pregnancy rate was significantly higher in the HIFU group (61.9%, 130/210) than in the non-HIFU group (38.6%, 49/127) (P<0.001). Multivariate analysis identified HIFU treatment (OR=2.728, P<0.0001) and an interval >3 years since the last cesarean section (OR=5.497, P=0.039) as significant predictors of higher re-pregnancy rates. Conversely, advanced age (OR=0.923/year, P=0.003), >3 cesarean sections (OR=0.255, P=0.037), and >3 induced abortions (OR=0.245, P=0.008) were associated with lower rates. Among the 179 patients who achieved pregnancy, RCSP incidence was significantly lower in the HIFU group (21.5%, 28/130) than in the non-HIFU group (42.9%, 21/49) (P=0.004). Multivariate analysis showed HIFU treatment reduced RCSP odds by 67.7% (OR=0.323, P=0.004), with thicker scars further lowering risk by 33.7% (OR=0.663/mm, P=0.021). Prior cesarean sections significantly increased RCSP risk (vs. 1 section: 2 sections OR=2.460, P=0.017; 3 sections OR=13.089, P=0.033; >3 sections OR=11.288, P=0.049).

Conservative surgery incorporating HIFU significantly improves re-pregnancy rates and reduces RCSP risk in CSP patients. Younger age, longer intervals since the last cesarean section, and fewer cesarean sections or abortions correlate with higher re-pregnancy rates. Thicker scar tissue and fewer cesarean sections are protective against RCSP. These findings warrant validation in larger prospective studies.