A 65-year-old woman comes to the office due to intermittent leakage of urine. For the past 3 months, the patient has had to change her undergarments multiple times a day due to urine leakage. She voids 4 or 5 times during the day and occasionally wakes up at night to void. The patient has type 2 diabetes mellitus and was recently diagnosed with chronic obstructive pulmonary disease after evaluation for a chronic cough. Her only surgeries were 2 cesarean deliveries in her 20s. BMI is 30 kg/m2. Pelvic examination shows leakage of urine from the urethra during the Valsalva maneuver. Postvoid residual volume and urinalysis are normal. Which of the following is the most likely cause of this patient's clinical presentation?
Show Explanatory Sources
This patient with intermittent leakage of urine likely has stress urinary incontinence (SUI). In women, the pelvic floor muscles contract to stabilize the urethra against the anterior vaginal wall. This contraction decreases the angle between the bladder neck and the urethra (ie, urethrovesical angle), thereby compressing the urethra, stopping urine flow, and maintaining continence.
Chronically increased intrabdominal pressure (eg, obesity, chronic cough from COPD) can cause weakened pelvic floor muscle support. In addition, prior pregnancies (including cesarean deliveries) typically increase the laxity of pelvic floor muscles and connective tissue. In patients with SUI, the weakened pelvic floor muscles can no longer stabilize the urethra, leading to urethral hypermobility, an increased urethrovesical angle, and resultant urinary incontinence (Choice A). On examination, patients typically have leakage of urine during the Valsalva maneuver. Patients with severe pelvic floor laxity can also develop herniation of the bladder into the vagina (ie, cystocele), which further worsens SUI symptoms.
Treatment can include pelvic floor muscle (ie, Kegel) exercises and pessary placement, which help support and maintain normal pelvic anatomy.
(Choice B) Vesicovaginal fistula is an abnormal connection between the bladder and vagina that most commonly occurs due to bladder injury from surgical or obstetric complications (eg, operative vaginal delivery). Unlike SUI, vesicovaginal fistulas cause continuous urinary dribbling rather than intermittent urinary leakage, and pelvic examination shows leakage of urine from the vagina (not the urethra).
(Choices C and D) The bladder receives both sympathetic and parasympathetic innervation to control continence and micturition. Sympathetic stimulation promotes urine storage and continence by increasing urethral sphincter tone. In contrast, parasympathetic activity stimulates detrusor muscle contraction and micturition. Therefore, increased bladder sphincter sympathetic activity or reduced detrusor parasympathetic activity would promote continence rather than the urinary leakage seen in this patient.
Educational objective:
Stress urinary incontinence (intermittent, involuntary leakage of urine) is caused by weakened pelvic floor muscle support that often occurs due to chronically increased intraabdominal pressure (eg, obesity, chronic cough, prior pregnancies).