Purpose: To expand the previously established age- and gender-specific nomograms of post-void
residual urine (PVR) from children to adolescents.

Material and Methods: Healthy children aged 2 to 16 years were enrolled for two sets of uroflowmetry and PVR. The first two consecutive PVRs of each child or adolescent with a voided volume >50 ml in participants >=6 years and >30mL in participants <=5 years were included for construction of PVR nomograms. Children with possible urinary tract infection or neurognenic lower urinary tract dysfunctions were excluded. All PVRs were assessed within 5 min after voiding with suprapubic ultrasound (Logiq Book1, GE Medical Systems, Milwaukee, WI), and estimated by the equation of height x width x depth x 0.52 ml. Bladder capacity (BC) was defined as voided volume + PVR.

Totally, 1663 children (841 boys and 822 girls) with a mean age of 9.9±3.9 years with 2752 PVRs were eligible for construction of PVR nomograms. The 95th percentile of PVR for all children was 32.6 ml, or 15.0% of bladder capacity (BC). 

The table showed the age and gender specific percentile of PVR and PVR/bladder capacity (PVR/BC) from age 2 to 16 years. The PVR and PVR/BC decreased as age increased before age of 12 years. The PVR increased after adolescence while PVR/BC remained stable at 10%. PVR was higher in boys than girls before age of 12 years. In adolescent, PVR was higher in girls. Table  Age and gender specific percentile of post-void residual urine (PVR) and PVR/bladder capacity (PVR/BC)

Conclusions: Age, gender, and BC should be taken into considerations at interpretation of PVR tests in children and adolescents because of gender- and age- differences in bladder function development.