Objective Mothers need reassurance that the breastfeeding behaviour of their babies is normal, but the range of normality and changes with stage of lactation have not been defined.

Methods Forty-two mothers of exclusively breastfed babies test-weighed their babies before and after every breastfeeding session for a 24-h period in their own homes at 1, 2, 4 and 6 months after birth. A breastfeeding session consisted of a feed from one or both breasts depending on the baby’s appetite.

Results There were 7.0 breastfeeding sessions a day (range 4–14), with fewest (6.4) at 2 months. Each breastfeeding session lasted 41 min (range 21–101 min) at 1 month decreasing to 28 min (range 11–54 min) at 6 months. The longest interval between breastfeeding sessions increased from 4 h 54 min (range 2 h 24 min–8 h 55 min) at 1 month to 6 h 52 min (range 3 h 29 min–10 h 30 min) at 6 months. The babies consumed 112 g at each breastfeeding session (range 58–227 g) with a maximum amount (136 g) at 2 months. The total milk production of the mothers was 821 g/24 h (range 464–1370 g/24 h) and did not change during the period of exclusive breastfeeding.

Conclusions There was at least a three-fold variation between infants in breastfeeding frequency, duration of breastfeeding sessions, longest interval between breastfeeding sessions, and milk intake. Mothers can be reassured that all babies do not need to show the same breastfeeding behaviour. During the lactation period babies can be expected to become more efficient, but will not increase their milk intake.

The authors receive research funding from Medela AG (Switzerland).