Effects of Gustatory and Olfactory Stimulation on Feeding Outcomes in Preterm Infants

BACKGROUND: Few primary studies have examined the impact of olfactory and gustatory stimulation on premature infants, and variability exists in reported outcomes. PURPOSE: To explore the effects of olfactory and gustatory stimulation on feeding outcomes in preterm infants. DATA SOURCES: A literature search was conducted in 4 databases (CENTRAL, PubMed, Embase, CINAHL) from the inception of the databases to May 2024. STUDY SELECTION: Randomized controlled trials (RCTs) or quasi-RCTs to explore the effects of olfactory and gustatory stimulation on feeding outcomes in preterm infants were included. DATA EXTRACTION: Two reviewers independently extracted data from the included studies and completed the form designed for data extraction. RESULTS: Eleven RCTs and quasi-RCTs comprising 1009 preterm infants were included. Meta-analysis found that olfactory and gustatory stimulation significantly shortened the time to reach full oral feeds ( days ) (mean difference [MD]: -2.52, 95% confidence interval [CI]: -3.88 to -1.16, P = .0003), while they had no significant differences in time to achieve full enteral feeds ( days ), postmenstrual age (PMA) at the removal of the nasogastric tube ( weeks ), weight at discharge ( grams ), weight gain ( grams ), head circumference at discharge ( cm ), length at discharge ( cm ), total duration of parenteral nutrition ( days ), necrotizing enterocolitis, hospitalization duration ( days ), PMA at discharge ( weeks ). IMPLICATIONS FOR PRACTICE AND RESEARCH: Large sample, multicenter studies are needed to demonstrate the effectiveness of olfactory and gustatory stimulation on feeding outcomes in preterm infants.