Feeding responses to free-flow formula in term and preterm infants.

OBJECTIVES

Although introducing freely flowing formula into the infant's mouth is a common feeding practice, its effect on feeding behavior is largely unknown. We evaluated the effects of free flow of formula from the nipple on infant feeding activity (sucking, swallowing, ingestion rate) and documented potential adverse behaviors such as cough, restless behavior, drooling, apnea, and bradycardia.

METHODS

We studied 13 preterm and 7 term infants. During a feeding, bottle pressure was adjusted every 2 to 3 minutes to increase or decrease free flow from the nipple.

RESULTS

Increase in free flow of formula from the nipple caused rapid increases in suck and swallow frequency in term and preterm infants and increased ingestion rate. The response was reversed by decreasing flow and was repeatable throughout the feeding. Peak suck and swallow rates were highest in term infants. Although drooling increased with increased milk flow, no effect of flow on coughing, restless behavior, or apnea was observed.

CONCLUSIONS

Free-flow formula is a potent stimulus for feeding activity in both preterm and term infants and is not associated with increased apnea or other adverse behaviors. The ability of the infant to divert excess formula flow by drooling is an efficient airway protective behavior. Reduced maximum suck and swallow frequency may be a primary basis for slow feeding in preterm infants.