Noninvasive evaluation of swallowing sound is an effective way of diagnosing feeding maturation in newborn infants

Aim: Despite extensive research, there is still controversy regarding the time at which sucking and swallowing functions mature in preterm infants. This study aimed to evaluate maturation using the noninvasive method of swallowing sound.

Methods: We compared 52 preterm infants of between 27 and 36 weeks' gestational age with a control group of 42 healthy full-term infants. Feeding performance was based on swallowing data collected during two-minute audio recordings. The following variables were generated for each evaluation: total number of swallows, total number of rhythmic swallows, total number of resting intervals, average time between resting intervals, average time between swallows, average time between rhythmic swallows, maximum number of rhythmic swallows and volume of milk ingested. The dependency of the variables on postmenstrual age was also investigated.

Results: The volume of milk ingested by the preterm infants and the maximum number of rhythmic swallows were positively correlated with postmenstrual age (PMA). The preterm infants reached the 10th percentile of the control infants at 34-35 weeks' PMA and were not significantly different from the control infants at 38-40 weeks' PMA.

Conclusion: Swallowing sound can be used to assess feeding maturation in preterm infants during neonatal intensive care unit follow-up.