OBJECTIVES: To analyze sphincter control acquisition in a birth cohort. METHOD: 4,231 children born in 2004 in Pelotas, Brazil, were included in a longitudinal study. During home visits at the ages of 12, 24 and 48 months, the mothers answered a questionnaire about sociodemographic questions and characteristics of their children's voiding and bowel habits, with special attention to toilet training. RESULTS: At 48 months, most children were off diapers during the day (98.5%) and by night (83%), with no difference between sexes. The average age for starting toilet training was 22 months, with earlier initiation in girls. The training was, on average, 3.2 months long, showing no difference between sexes. Children with developmental delay had late voiding and bowel control; the higher the deviation from normality, the later the child was off diapers. Medical advice was given to 15.9% of mothers. The training initiated before the age of 24 months was inversely correlated with an older age of sphincter control and longer training. Premature and low birth weight children showed no significant difference in training time and age of acquisition of sphincter control. CONCLUSIONS: At the age of 48 months, most children, including premature and low birth weight ones, acquired sphincter control regardless of external factors and sex. The beginning of training (before 24 months) did not anticipate sphincter control, but only prolonged the duration of training.
Toilet training; child; sphincter control; epidemiology
