Trends in breastfeeding: it is not only at the breast anymore.

The past characterisations of breastfeeding as being only at the breast of the mother may no longer be applicable in the United States as mothers now frequently express their milk. We conducted a retrospective cohort study with women who visited the Cincinnati Children's Breastfeeding Medicine Clinic to understand breast milk feeding behaviours of healthy mothers and infants, which included questions specifically about breast milk expression. All 40 mothers in the cohort expressed their milk and all 40 infants were fed expressed milk. One infant was fed another mother's milk for 30 days. Two-thirds (13/40) of infants received their mother's expressed milk at least a week after it was first expressed and 25% (10/40) of infants continued to be fed expressed breast milk after mothers had stopped expressing milk. There were 14 sequences of breast milk production by the mothers and 16 sequences of consumption by the infants. Early in the post-partum period, mothers started expressing milk even though their infants were consuming all of the breast milk that they needed at the breast. As a result of breast milk expression by all mothers in this cohort, we observed highly variable patterns of maternal breast milk production and infant breast milk consumption, which were not necessarily synchronous within a dyad. It is now time to develop appropriate ways to characterise the production and consumption of breast milk more accurately and investigate whether these behaviours have consequences for the health of mothers and infants.