Sucking patterns of human babies on the breast.

Twenty-seven 5--8-day-old babies were filmed during normal breast feeding (one feed each). Sucking patterns were determined from the film from a total sample of 17,676 sucks. Intersuck interals fell on two distributions: one of intervals between sucks during bursts of sucking (1.3 sec and less), and the other of rests between bursts of sucking (1.3 to greater than 12 sec). As the milk flow dropped towards the end of the feed on each breast, the sucking rate within bursts increased (P less than 0.05), but there were more (P less than 0.001) and longer (P less than 0.001) rests between bursts of sucking. This study provides normative data on a normal population for use in studies of breast feeding.