Is routine urinary tract investigation necessary for children with monosymptomatic primary nocturnal enuresis?

OBJECTIVES: To investigate in a prospective study the role of bladder function and to compare the results of urinary tract ultrasonography and urinalysis in children with and without primary nocturnal enuresis because, although this is a common problem in children, the etiology and mechanisms of the disorder have not been elucidated.

METHODS: The study included 106 children with monosymptomatic primary nocturnal enuresis and a control group of 57 children with no history of voiding dysfunction, aged 5 to 19 years. All children underwent urinalysis, bladder and upper urinary tract ultrasonography, and uroflowmetry. The bladder capacity, bladder wall thickness, and postvoid residual volume were measured using ultrasonography. The findings were compared between the enuresis and control groups according to age: 5 to 9 years, 10 to 14 years, and 15 to 19 years.

RESULTS: The mean age was 9.6 +/- 3.1 years in the nocturnal enuresis group and 9.4 +/- 3.3 years in the control group (P = 0.727). The mean number of defecations per week was significantly lower statistically in the enuresis group than in the control group in the age categories of 5 to 9 years and 10 to 14 years (P = 0.038 and P = 0.018, respectively), and the mean number of urinations per day was significantly higher statistically in the enuresis group than in the control group in the age groups of 5 to 9 years and 10 to 14 years (P = 0.002 and P = 0.001, respectively). The bladder capacity, bladder wall thickness, postvoid residual volume, uroflowmetry maximal flow rate, and average flow rate were not significantly different statistically between the children with primary nocturnal enuresis and the control group in the three age brackets. Urinary infection was detected in 2 children (1.88%) in the nocturnal enuresis group and none of the children in the control group (P = 0.547). Upper urinary tract abnormalities detected by ultrasonography were seen in 3 children (2.83%) in the nocturnal enuresis group and 1 child (1.75%) in the control group, revealing no statistical significance (P = 0.671).

CONCLUSIONS: Our findings show that the ultrasonographic and uroflowmetry findings on bladder function and the upper urinary system and the incidence of urinary infection are similar in children with and without nocturnal enuresis. Obtaining a voiding and elimination diary in conjunction with a good history may be beneficial in children with monosymptomatic primary nocturnal enuresis. In addition, routine urinalysis may be unnecessary in the evaluation of children with monosymptomatic primary nocturnal enuresis after obtaining a careful and complete history of the voiding dysfunction.