Infant feeding behavior development to 12 months with typical and slower-flow artificial nipples.

OBJECTIVES

To test the hypothesis that reducing artificial nipple flow rate reduces milk/formula intake and feeding efficiency while increasing feeding duration, and that the magnitude of the effect decreases with age. Sucking metrics were examined as exploratory outcomes.

METHODS

In a longitudinal cohort study, healthy, full-term infants were fed once in each of two experimental conditions, about one week apart, from ages one to twelve months: typical (Control) and slower (Intervention) flow rate nipple. Intake and feeding duration were measured and feeding efficiency calculated. The Nfant Bottle Solution™ measured suck duration, sucking burst duration, and sucking rate, and sucking efficiency was calculated.

RESULTS

Across infancy (n = 260), intake increased 2.91 g/mo (P < .01) in the Control but did not significantly change with age in the Intervention. Feeding duration decreased 0.68 min/mo (P < .001) in the Control and was reduced by 3.98min (P < .05) by the Intervention. Feeding efficiency increased 0.90 g/min/mo (P < .001) in the Control and 0.29 g/min/mo (P < .001) in the Intervention. Suck duration, burst duration, and sucking efficiency did not significantly change with age, but were reduced by the Intervention by 0.026s (P < .01), 13.68s (P < .05), and 0.09g/suck (P < .001), respectively. Sucking rate increased 0.02sucks/s/mo (P < .01) in the Control and did not significantly change with age in the Intervention.

CONCLUSIONS

Infants increase their intake as they grow older. Infants' adaptation to changing flow rates is limited, particularly among older infants. Future work should examine infants' adaptation to manipulating flow rate over a longer time period and effects on other outcomes.