Sucking and breathing patterns during breast- and bottle-feeding in term neonates. Effects of nutrient delivery and composition.

We attempted to determine whether differences in milk composition or flow rate are the primary determinants in altering breathing pattern during nipple-feeding. In the first phase of the study, 15 neonates were studied during breast-feeding and bottle-feeding; in the second phase, 15 were evaluated during bottle-feeding of expressed human milk and formula. A reduction in inspiratory duration was observed with all feeding regimens. Moreover, significant prolongation in expiratory duration and reduction in breathing frequency were observed during bottle-feeding of formula and expressed human milk (compared with control); these effects were greater with formula feeding. Higher sucking frequency was observed during breast-feeding compared with bottle-feeding; no difference in suckling frequency or sucking pressure was observed between bottle-feeding of expressed human milk and formula. We conclude that most of the differences in sucking and breathing patterns between breast- and bottle-feeding can be attributed to nutrient delivery rather than nutrient composition.