Effect of Smell and Taste of Milk on Feeding Parameters in Preterm Neonates: An Updated Meta-Analysis.

Smell and taste sensations have been linked to positive outcomes in the feeding of premature infants, though the impact on the time required to transition to oral feeding remains unclear. This study aimed to evaluate the beneficial effects of smell and taste interventions on clinical outcomes in preterm infants. We conducted a search in PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception through September 2024 for randomized controlled trials (RCTs) examining the effects of smell and taste on clinical outcomes in preterm infants with a gestational age of less than 34 weeks. The quality of the included studies was evaluated using the updated Cochrane's Risk of Bias tool (version 2). The primary outcome was the time required to achieve oral feeds. Secondary outcomes included the time to reach full enteral feeds, length of hospital stay, postmenstrual age, the need for parenteral nutrition, and the incidence of nosocomial infections. The outcomes were summarized as mean difference (MD) or odds ratio (OR) with 95% confidence intervals (CI) using a random-effects model. A total of 12 RCTs involving 1,638 preterm infants were included in the analysis. The results showed that smell and taste interventions significantly reduced the time needed to reach oral feeds (MD = -1.37 days, 95% CI [-2.26, -0.48], p < 0.001; I² = 42.15%) compared to no intervention. These findings were consistent across subgroup analyses based on birth weight at admission, type of exposure, and sample size. However, no significant differences were found for the other secondary outcomes. In conclusion, smell and taste interventions significantly reduced the time to reach oral feeds, with similar outcomes for other clinical measures compared to no intervention. These findings suggest that smell and taste interventions could be used in the care of preterm infants, with the need for large-volume RCTs and long-term assessments being warranted.