Establishing a mean postvoid residual volume in asymptomatic perimenopausal and postmenopausal women

OBJECTIVE: To estimate mean postvoid residual (PVR) volumes among perimenopausal and postmenopausal women without significant lower urinary tract or pelvic organ prolapse symptoms. METHODS: Patients presenting for well-women encounters were offered study participation. Women with a history of urinary incontinence greater than twice per week, urinary retention, symptomatic pelvic organ prolapse, or neurologic disorders were excluded. Pelvic relaxation, if present, was characterized according to the pelvic organ prolapse quantification system. Within 10 minutes of spontaneously voiding, PVR volume was assessed with bladder ultrasonography. RESULTS: A total of 96 patients were enrolled; mean age was 60±11 years. The majority (80%) were postmenopausal; 30% had a previous hysterectomy. Most women (92%) had some degree of prolapse; the median stage was one, most commonly involving the anterior compartment (70%). The median PVR volume was 19 mL (range 0-145 mL); the mean PVR volume was 24±29 mL. Only 15% of patients had a PVR volume greater than 50 mL, and 95% had a PVR volume 100 mL or less. Only age 65 years or older was associated with a higher mean PVR volume; hormone therapy, vaginal atrophy, parity, and stage of asymptomatic prolapse did not affect PVR volumes. CONCLUSION: Most asymptomatic perimenopausal and postmenopausal women had a PVR volume less than 50 mL, which was unaffected by multiple factors that were thought to potentially affect bladder function. Establishing "normal" volumes in this population may aid in developing recommendations regarding appropriate bladder function and retention criteria for women who are symptomatic or those who have had pelvic floor surgery.