Pacifier stiffness alters the dynamics of the suck central pattern generator

Abstract

This study examined the effect of varying pacifier stiffness on non-nutritive suck (NNS) dynamics at the NICU follow-up clinic among infants born prematurely with and without a history of respiratory distress syndrome. Three types of Soothie™ silicone pacifiers used in the NICU were tested for materials stiffness, revealing the Super Soothie™ is 7 times stiffer. No significant between-subjects effects were found for the healthy control infants and the RDS infants. However, Repeated-measures MANOVA within-group subjects effects showed significant differences in NNS cycles/min, NNS amplitude, NNS bursts/min, and NNS cycle periods between the Soothie™ versus Super Soothie™ pacifiers. Infants modify the spatiotemporal output of their suck central pattern generator when presented with pacifiers of different mechanical properties.