The physiologic coupling of sucking and swallowing coordination provides a unique process for neonatal survival

Although the coordination of sucking and swallowing is critical for successful oral intake in neonates, the mechanisms that facilitate this coordination are not well understood. This investigation sought to clarify the mechanisms that facilitate this coordination, by comparing sucks that were coordinated with swallows and sucks that were completed in isolation.

Ten neonates with a median gestational age of 28.2 weeks, ranging from 27.0 to 35.0 weeks, were recruited from the neonatal nurseries at Nationwide Children's Hospital, Columbus, Ohio, USA. They were evaluated while bottle-feeding at term gestation for differences in characteristics between sucks that were coupled and not coupled with swallows. Suction was evaluated using an intra-oral pressure transducer, and swallows were identified using a micromanometry pharyngeal catheter. Linear mixed models were applied to distinguish sucking characteristics.

Suction exhibited an antiphase relationship with the generation and release of positive pharyngeal pressure during the swallow. Coupled sucks had lower suction generation and release rates (p < 0.0001), lower suction amplitude (p = 0.004), longer suction duration (p < 0.0001) and higher milk ejection pressure (p < 0.0001).

The coordination of unique sucking and swallowing movement patterns may be achieved by the infant adapting sucking kinematics around the lingual patterns that facilitate the pharyngeal swallow.