Urethrovaginal reflux—a common cause of daytime incontinence in girls
Daytime incontinence of different causes occurs in 3.1% to 9.5% of school-age girls. (1-3) In most cases, isolated day wetting is found to be idiopathic, but incontinence may be a first symptom of a serious neurologic disorder. A correct diagnosis can often be obtained by child-adapted noninvasive procedures; only in special cases may invasive investigations be required.
Urethrovaginal reflux has been recognized as a possible cause of urinary leakage in girls. (4) Retrograde filling of the vagina is frequently found in association with voiding cystourethrography, even when performed in an erect position. (4,5) Such filling in young girls is usually viewed as a normal finding. The condition has mainly been considered in relation to suspected bacterial contamination of urine samples (4-6) and as a possible risk for urinary tract infection. (7) To our knowledge, the role of urethrovaginal reflux as the cause of incontinence has not been evaluated. The aims of the present study were to estimate the frequency of this condition in girls referred for treatment of daytime incontinence, and to study its characteristic symptoms and the effect of simple instructions intended to amend the problem.
MATERIALS AND METHODS
The frequency of urethrovaginal reflux was estimated in a consecutive sample of 169 girls, aged 7 to 15 years (median: 10 years), referred to a specialized urotherapeutic clinic because of daytime urinary incontinence. All girls were of normal weight and height, and apart from their incontinence, they were all healthy without known neurologic problems. They were evaluated by a noninvasive screening protocol including a careful history, clinical examination with particular focus on neurourologic status, bladder diary for 3 days, urine analysis, and 3 uroflowmetries followed by residual urine determination by ultrasound (Bladder-Scan 2500, Diagnostic Ultrasound Corporation, Redmond, WA).
All girls with a history of small urinary leakage shortly after daytime micturitions were further examined. The girls completed additional bladder diaries at home with extra focus on urinary leakage episodes 5 to 10 minutes after voidings (Fig 1). At the second visit, after confirmation of the diagnosis urethrovaginal reflux, they received instructions by a qualified urotherapist on how to sit properly on the toilet to void with minimal reflux and how to evacuate urine from the vagina (Table 1). The effect of instruction was evaluated by submitted bladder diaries and/or by telephone contact by the urotherapist.
[FIGURE 1 OMITTED]
Urethrovaginal reflux was identified as the cause of daytime urinary leakage in 21 (12.4%) of 169 girls. They all had a characteristic pattern of leakage in connection with voidings. Typically, they were dry when going to the toilet but frequently wet their panties within 5 to 10 minutes after the voiding. This pattern was easily discovered by adequate questions during history taking and supported by the specific bladder diary, as shown in Fig 1 from a typical girl with urinary leakages at 5 of 6 voidings during the day. Characteristically, the leakages were rather small but enough to wet the panties.
Although not necessary or specific for the diagnosis, (4,5) urethrovaginal reflux can frequently be observed in micturition cystourethrography (Fig 2). The illustrated investigation was performed to exclude ureteric reflux in a girl with repeated distal urinary tract infections. In practice, the diagnosis of urethrovaginal reflux is obtained by the finding that the girls can evacuate urine from the vagina after voidings. Furthermore, their incontinence problem is resolved by teaching them how to sit and void to minimize vaginal reflux and how to empty the vagina (Table 1).
[FIGURE 2 OMITTED]
The girls with urethrovaginal reflux had the same age distribution, 7 to 15 years, as the total group of girls with daytime incontinence. There was no obvious deviation in the shape of their urethral meatus, external genitals, or hymenal ring compared with the normal anatomy of girls in the same age group. Their neurourologic findings were also normal. Voiding frequency was 4 to 8 voidings per day (median: 5), which is within the normal range for healthy school-aged girls. (8) All but 1 had normal urinary flows; the exceptional girl had several voidings with interrupted flow curves. She and another girl were the only ones who voided with residual urine (>20 mL). Both girls also had asymptomatic bacteriuria, as did a third girl without signs of bladder dysfunction. For the remaining 18 girls, the urine analysis was normal. However, 6 had a previous history of 1 (2 girls) or more (4 girls) episodes of acute cystitis. Despite referral because of daytime incontinence, 3 girls had primary nocturnal enuresis. This elaborate list should not conceal that the majority of the girls with urinary leakage attributable to urethrovaginal reflux had normal bladder function at the time of evaluation.
All girls with urethrovaginal reflux received a thorough voiding instruction by a qualified urotherapist, as outlined in Table 1. Their problem with postmicturition urinary leakage immediately resolved. At follow-up (median: 2 years), all girls but 2 remained continent and all but 1 with recurrent acute cystitis became free from urinary tract infections. For these 19 girls (11.2%), the urethrovaginal reflux was apparently the sole cause of their daytime urinary leakage. The 2 girls, who at first visit had residual urine, remained incontinent with cystometrically proven phasic detrusor overactivity. Both had lasting asymptomatic bacteriuria, and 1 had lasting residual urine. Clearly, the original leakage problem of these girls was attributable to a combination of urethrovaginal reflux and urge incontinence. The third girl with asymptomatic bacteriuria became dry despite remaining bacteriuria. At follow-up, the 3 girls with nocturnal enuresis were all dry at night.
Urethrovaginal reflux is a surprisingly common cause of urinary leakage in schoolgirls. It was the major problem in >10% of the girls referred to a specialized clinic for daytime incontinence. The diagnosis is easily obtained by a careful history, completed with an adequate bladder diary. In affected girls, the anatomy of the urethral meatus and external genitals is apparently normal for the age. Most affected girls also have a normal bladder function. The condition is very gratifying to handle, because it is rapidly amended by proper instructions about voiding position and how to evacuate the vagina from reflux urine.
The mechanisms behind urethrovaginal reflux are not quite clear. Presumably, the problem arises from the specific anatomic situation in young girls, as the condition is not found in postpubertal girls or women. In young girls, the urethral opening is close to the vagina and hymenal ring with the labia minora and majora small and in close proximity. Even without anatomic adhesions, the labia may stick together and direct the urine backwards. Therefore, the urine may pass through the vaginal opening and stay behind the low barrier of the hymen. The vagina has also a more horizontal position before puberty, which may contribute to the vaginal reflux.
When the girl rises from the toilet, urine will start to dribble and wet the panties. For some girls, the majority of leakage may occur when they start to move. Others may squeeze out urine first when they increase the abdominal pressure by laughing or coughing. In most cases, the leakage is just a few milliliters, which is enough to leave a wet spot in the panties. The described course of events explains the typical history of girls with urethrovaginal reflux–they are dry when going to the toilet but wet when leaving.
Urethrovaginal reflux is frequently found when performing voiding cystourethrography (4-6) in girls. Such findings are not diagnostic, because most girls with radiologically demonstrated reflux have no symptom of urinary leakage. Either the vagina is not filled during everyday voidings or empties spontaneously before the girl gets up from the toilet. Whatever the case, this finding has caused some concern regarding bacterial contamination of urine samples for culture. (4-6) It can be expected that urethrovaginal reflux in some girls may cause genital irritation, smarting, bad smell, and vaginal discharge. The condition may also contribute to lower urinary tract infections. (7) In agreement, a relatively high proportion of the girls with urethrovaginal reflux (43%) had a history of urinary tract infections. Most became free of infections when their problem with urethrovaginal reflux resolved.
Urethrovaginal reflux is a surprisingly common cause of daytime urinary leakage in girls. The condition is easily diagnosed by an adequate history and amended by instructions aimed at improving toilet habits. With no need for specialized urologic investigations, the outpatient pediatrician can properly handle the condition.
TABLE 1. Voiding Instructions for Girls With Urethrovaginal
Sit steadily on the toilet brim, legs fully supported.
Keep the legs well apart.
Lean the trunk forward (as much as you can) making the pelvic
tilt forward and the urinary stream more vertical.
Separate the labia before voiding.
At end of voiding, use toilet paper to press and lift the
perineum forward/upward (from the base of the vagina and
away from the rectum) to empty urine from the vagina.
Fig. 1 A typical bladder diary for a 9-year-old girl with daytime
urinary leakage caused by urethrovaginal reflux.
Bladder diary for urethro-vaginal reflux (Condensed)
Name: M S
Date of birth: March 3rd 1990 Date: March 25th 1999
Before voiding After voiding (5-10 min)
Time Wet Damp Dry Voided volume Wet Damp Dry Comments
7.00 X 240 ml X
11.00 X 175 ml X
15.00 X 140 ml X
17.00 X 120 ml X
19.00 X 150 ml X
21.00 X 50 ml X
The study was supported by grants from Ostergotlands Landsting and from the Research Fund of the University Hospital of Linkoping.
Urotherapists Monica Eldh and Monica Brannstrom and specialist nurse Kerstin Rydmyr provided voiding instructions to the girls. Assistant Professor Margareta Resjo kindly supplied the radiograph.
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Sven Mattsson, MD, Med Dr, and Gunilla Gladh, RN, Med Dr
From the Division of Pediatrics, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linkoping, Sweden.
Received for publication Mar 14, 2002; accepted July 30, 2002.
Reprint requests to (S.M.) Division of Pediatrics, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, SE-581 85 Linkoping, Sweden. E-mail: email@example.com
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