Age Related Nocturnal Urine Volume and Maximum Voided Volume in Healthy Children: Reappraisal of International Children's Continence Society Definitions

Purpose: We determined normal, age related reference data regarding maximum voided volume and nocturnal urine production using the same methodology as in clinical practice.Materials and Methods: A total of 62 girls and 86 boys without enuresis (mean ± SD age 9.64 ± 2.63 years, range 3 to 15) completed 4 days (2 weekends) of frequency-volume charts and 14 days of home recording of nocturnal urine production. From these recordings maximum voided volume with and without first morning void was derived for each subject. Also, average nocturnal urine volume with and without nocturia was calculated. Percentiles were produced by dividing the population into 1-year age groups.Results: Based on 2,836 daytime voids and 1,977 overnight recordings, maximum voided volume and nocturnal urine volume showed a significant linear relationship with age but not with gender. Maximum voided volume with first morning void was significantly higher than without (403 ± 137 ml vs 281 ± 112 ml, p <0.0001) and the 50th percentile line...