Muhammad Sharjeel Ilyas^1*, Nimrah Naushad¹

¹Akhtar Saeed Medical & Dental College, University of Health Sciences, Lahore, Pakistan

^*Corresponding address: Akhtar Saeed Medical & Dental College, University of Health Sciences, Lahore, Pakistan

Email: sharjeel_ilyas@hotmail.com

Received: 10 March 2025 / Revised: 26 May 2025 / Accepted: 31 May 2025 / Available Online: 20 June 2025

DOI: https://doi.org/10.63137/jsteam.636487

ABSTRACT

Objective: Establishing oral feeding in preterm neonates in the intensive care setting is a notable clinical challenge. Delayed transition from enteral to oral feeding increases the risk of adverse outcomes and prolongs hospitalization. Emerging evidence suggests that olfactory stimulation may enhance feeding readiness by engaging sensory pathways critical for suck-swallow coordination. This systematic review seeks to determine the effect of olfactory stimulation on the timeline for premature neonates to reach full oral feeding.

Methods: Adhering to PRISMA guidelines, an extensive literature search was performed utilizing PubMed and Scopus databases from 2015 to 2024. Eligible studies were randomized controlled trials (RCTs) involving preterm infants (26–34 weeks of gestation) who received olfactory stimulation (e.g., milk, vanilla, rose odors) compared to standard care. The primary outcome was the number of days required to achieve full oral feeding. Data were synthesized using a random-effects meta-analysis model, and methodological quality was assessed using the Cochrane RoB 2 tool and GRADE framework.

Results: Out of 1,029 identified records, five RCTs met the inclusion criteria. Meta-analysis showed that olfactory stimulation significantly reduced the time to full oral feeding (mean difference = -1.37 days; 95% CI: -2.36 to -0.39; p = 0.006), with high heterogeneity (I² = 98%). Subgroup analyses indicated the greatest benefit in studies using milk odor and in smaller cohorts.

Conclusion: A safe and non-invasive strategy, olfactory stimulation appears to facilitate a quicker transition to full oral feeding in preterm infants. However, future research, particularly large-scale studies, is required to ascertain its long-term efficacy and refine intervention protocols.

Keywords: Enteral nutrition; Feeding behavior; Infant, Premature; Olfactory stimulation; Randomized controlled trial

Data Availability: The data supporting this study are available from the corresponding author upon reasonable request.

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How to Cite: Ilyas MS, Naushad N. Enteral to Oral Feeding Progression by Olfactory Stimulation in Preterm Infants, A Systematic Review. J Sci Technol Educ Art Med. 2025;2(1):43-50