L26/P-358 Abnormal uterine peristalsis in endometriosis and its modulation after surgery revealed by non-invasive electrophysiological imaging

Abstract Study question Does uterine peristalsis pattern differ in women with endometriosis compared with physiological patterns, and does it change following surgery? Summary answer Endometriosis showed increased uterine peristalsis magnitude and power, shorter duration, and fewer non-directional patterns during menses phase; surgery significantly normalized these abnormalities. What is known already Endometriosis is known to be associated with altered uterine contractility and abnormal peristaltic activity, which may contribute to pelvic pain and impaired reproductive function. Previous studies have primarily relied on imaging or invasive techniques to characterize uterine peristalsis, often focusing on qualitative or cross-sectional assessments. However, quantitative characterization of uterine peristalsis using non-invasive electrophysiological approaches remains limited. How peristaltic magnitude, temporal dynamics, and directional organization differ in endometriosis and how these features change following surgery are not well understood. Study design, size, duration This observational study included 26 endometriosis patients (6 pre-surgery and 20 post-surgery) and 14 naturally cycling controls, enrolled from 2021 to 2025. Uterine peristalsis imaging (UPI) was performed during the menses phase for all the participants. Patients were all not on hormonal therapy at the time of UPI study. Participants/materials, setting, methods UPI was performed using transabdominal ultrasound and electrode patches to capture uterus-body surface geometry. Signals were recorded for 20-30 minutes. UPI software analyzed the frequency, duration, magnitude, power and direction. Group differences were analyzed using the Rank-Sum test. Main results and the role of chance Age and BMI did not differ significantly (Age: p = 0.46 and 0.74; BMI: p = 0.41 and 0.13, respectively) between pre-surgery endometriosis (29 ± 5.4 years; 29.1 ± 5.8 kg/m2), post-surgery endometriosis (31.3 ± 3.6 years; 26.5 ± 4.6 kg/m2), and the control group (28.29 ± 5.1 years; 25.1 ± 4.5 kg/m2) Before surgery, women with endometriosis exhibited significantly higher uterine peristalsis magnitude compared with physiological patterns (p = 0.0025), accompanied by increased power (p = 0.004) and a significantly lower proportion of non-directional peristalsis (p = 0.004), while peristaltic duration showed a decreasing trend. Among patients who underwent surgery, uterine peristalsis magnitude was significantly lower post-operatively than pre-surgery (p = 0.0026), whereas peristaltic duration increased significantly (p = 0.007). Peristalsis power was significantly reduced following surgery (p = 0.01), and the proportion of non-directional peristalsis increased significantly (p = 0.01). These between-group and within-patient differences were statistically significant, indicating that the observed alterations were unlikely to be attributable to chance alone. Limitations, reasons for caution Small sample size limits statistical power. Peristalsis was categorized into only three patterns (C-F, F-C, and other), potentially overlooking additional important dynamics. Wider implications of the findings These findings suggest that non-invasive electrophysiological imaging may provide an objective approach to characterizing uterine peristalsis abnormalities in endometriosis and to monitoring functional changes following surgery, with potential relevance for phenotyping disease activity and guiding future clinical assessment. Trial registration number No