title: Voiding pattern and acquisition of bladder control from birth to age 6 years--a longitudinal study.
abstract: OBJECTIVE
  We describe the voiding pattern and acquisition of bladder control in healthy children up to age 6 years.
  
  
  METHODS
  We determined age for daytime and nighttime dryness, voiding patterns, voiding volumes and post-void residual volume per 4 hours individually and noninvasively every 3 months up to age 3 years and every 6 months up to age 6 years in 36 female and 23 male patients using 4-hour voiding observation and uroflowmetry/ultrasound.
  
  
  RESULTS
  Median age for attaining daytime and nighttime dryness was 3.5 and 4 years, respectively. No significant difference was found between girls and boys. All but 1 child attained daytime dryness an average of 10 months before attaining nighttime dryness. Bladder sensation was reported in 31%, 79% and 100% of patients at ages 2, 3 and 4 years, respectively. Median bladder capacity was 67 ml, 123 ml and 140 ml at years 1, 3 and 6, respectively. Median post-void residual volume was 5.5 ml, 0 ml and 2 ml at ages 1, 3 and 6 years, respectively.
  
  
  CONCLUSIONS
  Today bladder control is acquired at a later stage despite earlier awareness of bladder function. The occurrence of bladder sensation from age 1.5 years motivates an earlier start with toilet training. Infants with small post-void residual volume at age 6 months or large bladder capacity will probably attain daytime dryness earlier than those with large post-void residual volume at age 6 months or small bladder capacity.
authors.affiliation: Department of Surgery, Queen Silvia Children's Hospital and Sahlgrenska Academy, Göteborg, Sweden. ullabritt.jansson@vgregion.se
authors.forename: U-B
authors.initials: UB
authors.lastname: Jansson
authors.forename: M
authors.initials: M
authors.lastname: Hanson
authors.forename: U
authors.initials: U
authors.lastname: Sillén
authors.forename: A-L
authors.initials: AL
authors.lastname: Hellström
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D014039:Toilet Training; D001743:Urinary Bladder / Q000502:physiology*; D014554:Urination