A 32-year-old woman comes to the office due to leakage of urine. The leakage started a year ago and occurred occasionally while the patient was exercising but recently has worsened significantly. She states, "I leak urine every time I work out, particularly when I lift weights. I have been training for a triathlon and wanted to increase my strength, but now if I lift more than 15 kg (33 lb), I soak through my underwear." For the past month she has skipped workouts due to embarrassment from the leakage. The patient reports frequent urination and awakens 1 or 2 times at night to urinate. She has no dysuria or hematuria. The patient has no chronic medical conditions. She has had 2 cesarean deliveries but no other surgeries. The patient takes oral contraceptives and a daily multivitamin. She drinks 4 L (1.06 gal) of water daily but can double her intake on workout days. The patient does not use tobacco, alcohol, or illicit drugs. Blood pressure is 110/70 mm Hg and pulse is 58/min. BMI is 26 kg/m². Pelvic examination reveals a normal-sized, anteverted uterus and no adnexal masses. Speculum examination shows a well-rugated vagina and no evidence of pelvic organ prolapse. Leakage of urine is observed when the patient is asked to cough. Serum electrolytes are normal. A urinalysis has a specific gravity of 1.001 but is otherwise within normal limits. Which of the following is the most likely cause of this patient's symptoms?

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Explanation: 11ec2b69_bf15_571b_8f63_f1f958963402_MD0005_00 This patient has stress urinary incontinence (SUI) based on urinary leakage with Valsalva (eg, weight lifting) and a positive cough-stress test. SUI is typically a sequela of pelvic trauma (eg, vaginal delivery), age-related connective tissue loss, or chronic elevated intraabdominal pressure (eg, high-impact exercise), all of which can cause inadequate urethral support. With inadequate support, the urethra becomes hypermobile and unable to close adequately. SUI is a common cause of urinary incontinence in younger women. Additional risk factors include obesity, increased parity, increasing age, tobacco use, and caffeine use. Initial treatment for SUI includes pelvic floor muscle exercises (Kegel) and lifestyle changes such as caffeine restriction, weight loss, and smoking cessation. This patient's water intake is likely contributing to her symptoms; limiting water intake to 2 L (0.53 gal) daily will likely improve both urinary frequency and SUI symptoms. Patients who do not improve with conservative measures are candidates for surgical management, typically a mid-urethral sling procedure. (Choice A) Overflow urinary incontinence can be caused by bladder outlet obstruction and presents with constant urinary dribbling, a weak urinary stream, and incomplete bladder emptying. However, bladder outlet obstruction typically occurs in men with benign prostatic hypertrophy or in women as a complication of a mid-urethral sling procedure. (Choice B) Detrusor muscle overactivity is a cause of urgency urinary incontinence (ie, overactive bladder), which typically presents with a sudden, overwhelming urge to void followed by an involuntary loss of urine. (Choice C) Intrinsic sphincteric deficiency, a urethral sphincter weakness that prevents the urethra from closing completely, is the result of neuromuscular damage that typically occurs during pelvic surgery or vaginal delivery. This diagnosis is unlikely in this patient who has had only cesarean deliveries. (Choice D) Primary polydipsia is a compulsive, excessive fluid intake typically seen in patients with a concomitant psychiatric illness. Patients with polydipsia have dilute urine (eg, low specific gravity) and polyuria; however, they also have hyponatremia, not seen in this patient. Educational objective: Stress urinary incontinence is the involuntary leakage of urine with increased intraabdominal pressure. It occurs when pelvic trauma, loss of pelvic connective tissue, or high-impact activity causes inadequate urethral support and urethral hypermobility. References: Clinical management of urinary incontinence in women. (http://www.ncbi.nlm.nih.gov/pubmed/23668526) Diagnosis of urinary incontinence. (http://www.ncbi.nlm.nih.gov/pubmed/23668444)

A 32-Year-Old Woman Comes to the Office Due to Leakage