Introduction:
Overactive bladder (OAB) symptoms are common in women with pelvic organ prolapse (POP), negatively impacting quality of life. Previous studies suggest bladder wall thickness (BWT) may serve as a marker of bladder dysfunction. Its role in predicting surgical outcomes remains under investigation.
Objectives:
To determine whether reductions in BWT after POP surgery are associated with improvements in urinary urgency and frequency in women with coexisting OAB.

Materials and Methods:
This prospective cohort study included 169 women with stage ≥2 anterior POP and OAB symptoms. BWT was measured via transvaginal ultrasound at three sites (anterior wall, trigone, dome) preoperatively and at 3 and 6 months postoperatively. Symptom changes were assessed using OABSS and ICIQ-OAB. Non-parametric tests and ROC analysis were performed.

Results:
BWT significantly decreased in all regions postoperatively (Δ anterior: –1.34 mm; trigone: –1.35 mm; dome: –1.33 mm; all p<0.001). Frequency and urgency symptoms improved in 76.3% and 64.5% of patients, respectively. ROC analysis identified optimal BWT reduction thresholds of ≥0.80 mm for frequency (AUC: 0.90) and ≥0.85 mm for urgency (AUC: 0.93). For urgency improvement, dome wall reduction of ≥0.85 mm yielded sensitivity of 93.5% and specificity of 81.7%.

Symptoms of overactive bladder (OAB) in women who are having pelvic organ prolapse (POP) surgery are frequently observed, with 82% experiencing urinary frequency or urgency and 40% suffering from urinary incontinence that is bothersome; these symptoms are linked to both the compartment affected and the severity of the prolapse. The presence of symptoms was found to be more closely related to the anterior and apical compartments compared to the posterior compartment. The severity of urinary frequency and urgency urinary incontinence decreased after surgery for all compartments (anterior, apical, anterior and apical, posterior) during the 6-month follow-up. BWT  after POP surgery is  associated with OAB symptoms.

Conclusion:
Greater BWT reduction after POP surgery is strongly associated with OAB symptom improvement. BWT thresholds show high predictive accuracy, supporting their potential use in preoperative planning and prognostic counseling.