Effectiveness of Non-Nutritive Sucking on Sucking Performance in Preterm Infants: A Systematic Review

Non-nutritive sucking (NNS) is commonly employed to assist in the development of preterm infants facing feeding challenges. The effectiveness of NNS interventions on sucking performance (suction and expression/compression component of sucking) in this population has not yet to be systematically explored. To review the literature on the effects of NNS on sucking performance in preterm infants. A comprehensive search was conducted across five databases, encompassing publications from the inception of these databases until July 2024. The studies included only randomized controlled trials (RCTs) involving preterm infants born before 37 wk with feeding problems, who were tube-fed. The experimental group received exclusive NNS intervention, while the control group received routine care or no intervention. Data extraction focused on one primary outcome (sucking performance) and two secondary outcomes (physiological characteristics and weight gain at discharge). The quality of the included studies was assessed using the Physiotherapy Evidence Database (PEDro) scale, while the Cochrane risk-of-bias tool for randomized trials was employed to evaluate the risk of bias. The findings were summarized using a narrative synthesis approach. Nine RCTs involving a total of 575 preterm infants were incorporated. The methodological quality scores of the included studies ranged from 5 to 8. Compared to standard care, the use of NNS had positive influences on the Lower Anchors and Tethers for Children (LATCH) scale, aspects of sucking parameters (the percentage of milk taken and number of sucks per burst), and physiological characteristics. However, NNS produced variable results on the Preterm Infant Breastfeeding Behavior Scale (PIBBS), weight gain at discharge, and four sucking parameters—volume of milk intake at the first 5 min, rate of milk transfer, overall milk intake, and feeding time. Notably, insignificant association was found between NNS and other sucking parameters, including overall frequency, suction amplitude, and expression amplitude. The effectiveness of NNS intervention on sucking performance, weight at discharge yielded inconsistent results. However, the existing evidence that elucidated the impact mechanism of NNS and its effects on sucking performance was constrained. Additional trials characterized by robust methodological quality should be employed to further elucidate and clarify the potential impact mechanism of NNS on sucking performance.