Abstract
There is no doubt that human breast milk is the ideal source of nutrition for the growing infant in the first year of life, but there remains the question: Does the mode of feeding make any difference as long as the infant receives his mother’s milk? Simply put, does nursing at the breast provide any advantages to the infant as compared to what would result from bottle feeding of expressed (pumped) milk?
This is far from a theoretical question. The reality of the life/work style of women, particularly in the developed world, has resulted in an increased use of bottle feeding of pumped milk to supplement or even replace breastfeeding, especially as they return to the workplace. Most strikingly, there is the phenomenon (mostly anecdotal) of planned exclusive bottle feeding of pumped milk by mothers from the immediate postpartum period. Some would say that this is parallel to the phenomenon of routine, nonmedically indicated elective cesarean sections as a normative and routine mode of delivery. Yes, convenience and not medicine is the driving force for such decisions.
Previous studies of the infant growth patterns of bottle-fed infants’ (i.e., formula-fed) have documented an excessive weight gain trajectory compared to those exclusively nursed. 1 This is of particular concern given the finding that rapid weight gain during infancy is an additional risk factor for later-life obesity. 2
Thus, the particular interest and topicality of last month’s issue of Breastfeeding Medicine, which highlighted a comprehensive critical review by Slater and coworkers 3 entitled: “Comparison of the Effect of Direct Breastfeeding, Expressed Human Milk, and Infant Formula Feeding on Infant Weight Trajectories: A Systematic Review.” The bottom line from their analysis was that, despite the methodological limitations in many of the individual reports, there is sufficient evidence that bottle feeding is the culprit causing excessive weight gain, irrespective of whether it contains expressed breast milk or formula.
Bottle-fed infants are simply overfed, as the infant in its functionally passive status loses the ability to self-regulate the amount of milk ingested, resulting in a situation where there is no longer satiation-guided nursing. Bottle feeding of human milk is also all too frequently a mistimed feeding4,5 in the sense that the infant is fed breast milk which was expressed at a different time from when it is fed, ignoring the variations of the milk constituents that follow a maternal circadian rhythm pattern.
No less important is that with bottle feeding, there is frequently no or minimal physical interaction with the mother, resulting in disruption of what would be the normal maternal–infant synchronous interaction that facilitates infant development and maternal well-being.6,7
The message is clear: the normative, biologically determined infant feeding process is to nurse (suckle) at the mother’s breast and that delivering the milk in an artificially non-nature-designed way is not a substitute and should be minimized as much as practically feasible for the well-being of the mother–infant dyad.