Standardized 4D Transperineal Ultrasound Assessment of Urethrovesical Junction Mobility After Vaginal Laser Treatment for Stress Urinary Incontinence.

Inclusion Criteria: * Female sex. * Age 18 years or older. * Pure stress urinary incontinence or stress-predominant mixed urinary incontinence. In women with mixed urinary incontinence, the stress component must be the dominant and most bothersome symptom. * Urodynamically demonstrated stress urinary incontinence. * Absence of detrusor overactivity on urodynamic testing. * Independent decision to undergo self-paid vaginal laser treatment as routine clinical care, made before the offer of study participation. * Ability to complete the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF). * Ability to perform a technically acceptable Valsalva maneuver. * Willingness to attend the scheduled follow-up visits. * Written informed consent to study participation. Exclusion Criteria: * Predominant overactive bladder or predominant urgency urinary incontinence. * Previous surgery for stress urinary incontinence. * Previous vaginal laser treatment. * Previous pelvic organ prolapse surgery. * Pelvic Organ Prolapse Quantification (POP-Q) stage II or greater in any compartment. * Current pessary use at enrollment. * Active pelvic floor physiotherapy at enrollment. * Previous pelvic radiotherapy. * Pregnancy. * Unexplained genital bleeding. * Pelvic malignancy. * Any other contraindication to vaginal laser treatment. * Active urinary tract or vaginal infection. Enrollment and laser treatment will be deferred until the infection has resolved.