Does the choice of bottle nipple affect the oral feeding performance of very-low-birthweight (VLBW) infants?

Abstract

Background: There is a continuous debate regarding the best bottle nipple to be used to enhance the bottle-feeding performance of a preterm infant.

Aim: To verify that feeding performance can be improved by using the bottle nipple with the physical characteristics that enhance infants' sucking skills.

Methods: Ten "healthy" VLBW infants (941+/-273 g) were recruited. Feeding performance was monitored at two time periods, when taking 1-2 and 6-8 oral feedings/d. At each time and within 24 h, performance was monitored using three different bottle nipples offered in a randomized order. Rate of milk transfer (ml/min) was the primary outcome measure. The sucking skills monitored comprised stage of sucking, suction amplitude, and duration of the generated negative intraoral suction pressure.

Results: At both times, infants demonstrated a similar rate of milk transfer among all three nipples. However, the stage of sucking, suction amplitude, and duration of the generated suction were significantly different between nipples at 1-2, but not 6-8 oral feedings/d.

Conclusion: We did not identify a particular bottle nipple that enhanced bottle feeding in healthy VLBW infants. Based on the notion that afferent sensory feedback may allow infants to adapt to changing conditions, we speculate that infants can modify their sucking skills in order to maintain a rate of milk transfer that is appropriate with the level of suck-swallow-breathe coordination achieved at a particular time. Therefore, it is proposed that caretakers should be more concerned over monitoring the coordination of suck-swallow-breathe than over the selection of bottle nipples.

Figure 1

Schematic of the bottle nipple apparatus for the monitoring of sucking. PT: pressure transducer; PE200: polyethylene tubing.

Figure 2

Stages of sucking by nipple type: (a) at 1–2 oral feedings per day (F=5.442, df=2, p=0.028); (b) at 6–8 oral feedings per day (F=0.751, df=2, p=0.486). ^⋆Post hoc significance.

Figure 3

Suction amplitude (mmHg): (a) at 1–2 oral feedings per day (F=4.170, df=2, p=0.033); (b) at 6–8 oral feedings per day (F=2.052, df=2, p=0.164).

Figure 4

Duration of generated suction (s): (a) at 1–2 oral feedings per day (F=7.278, df=2, p=0.005); (b) at 6–8 oral feedings per day (F=0.970, df=2, p=0.380). ^⋆Post hoc significance.