Evaluation of bladder capacity in Korean children younger than 24 months: a nationwide multicenter study

Bladder capacity is an important factor in the diagnosis and treatment of children with voiding dysfunction. The purpose of this study was to define the normal maximal voided volume formula in Korean children younger than 2 years.

We measured the bladder capacities of 151 Korean children between 0 and 24 months of age (83 boys and 68 girls) who did not have clinical voiding dysfunction. The maximal voided volume was determined in all subjects using a 2-day frequency volume chart with a four-hour voiding observation. The largest voided volume for each patient was considered to be the maximal voided volume. Statistical analyses were carried out using linear regression analysis.

The maximal voided volume increased with age and weight (P = 0.0001). There was no significant difference between males and females (P = 0.771). A formula that approximates bladder capacity with respect to age is the following: bladder capacity (ml) = [1.6 × age (months)] + 45 (t = 8.757, P = 0.0001). A formula that approximates bladder capacity with respect to weight is the following: bladder capacity (ml) = [4.1 × weight (kg)] + 28 (t = 10.152, P = 0.0001).

These formulas may be useful for the diagnosis of abnormal bladder capacity and the evaluation of voiding dysfunction in Korean children younger than 24 months.