The Effects of Pleasant Odors on Transition From Gavage to Oral Feeding in Preterm Infants: A Systematic Review and Meta-analysis

Background: Gavage feeding is associated with adverse effects, such as irritations in the mouth, hyperactivity, problems in gag reflex, bradycardia, and the parents' unacceptance. Accordingly, it is essential to undertake a comprehensive review of the effects of breast milk and other pleasant odors that may reduce the transition time from gavage to oral feeding in preterm infants. Objectives: Aim of review is to compare of effects of breast milk and other pleasant odors with the control group on the transition from gavage to oral feeding in preterm infants. Methods: In this systematic review, online English databases, such as PubMed, Scopus, ISI Web of Science, and Cochrane Library were systematically searched without any time limitation up to February 10, 2022. The modified Jadad scale was also used to assess the quality of the articles. The inclusion criteria comprised all clinical trials evaluating the effect of aromatherapy on odors on the transition from gavage to oral feeding in preterm infants. Results: 8 studies were assessed with the effects of aroma inhalation on the transition from gavage to oral feeding. Meta-analysis of these studies showed that preterm infants transitioned from tube feeding (gavage) to oral feeding earlier in the groups stimulated by pleasant odors (standardized mean difference [SMD]=-0.47, 95% CI,-0.64%,-0.3%, heterogeneity, P=0.32; I 2 =13%, 8 trials) and odor of breast milk (SMD=-0.61, 95% CI,-0.64%,-0.31%, heterogeneity, P=0.85, I 2 =0%, 6 trials) in comparison to the control group. Conclusions: Our meta-analysis supports using breast milk and other pleasant odors as a safe and noninvasive way of reducing the transition time from gavage to oral feeding in preterm infants. Health providers should use effective and family-friendly interventions to care for their premature infants.