Environmental factors and clinical markers of stress during neonatal transport: a systematic literature review

Abstract

Background: Neonatal transport is an essential component of modern neonatal intensive care globally, providing access to advanced treatment while exposing vulnerable neonates to environmental conditions that may increase the risk of physiological instability.

Objective: To systematically review studies measuring environmental exposures, specifically vibration, sound and temperature fluctuations during neonatal transport and to evaluate their impact on clinical parameters in neonates.

Methods: A systematic literature review identified studies reporting environmental factors or clinical data during transport via ground, rotor or fixed-wing air ambulances. The medical databases searched included MEDLINE/PubMed, Embase, the Cochrane database of systematic reviews, Nursing Reference Center Plus, UpToDate and SveMed covering the period from November 2020 to January 2025.

Results: 15 observational studies, 13 prospective and 2 retrospective covering publications from 1992 to 2025 were included. The studies included data on vibration, sound, ambient temperature and a wide range of clinical parameters such as heart rate and heart rate variability, change in clinical behaviour scales and cortisol in saliva reflecting the neonatal condition. Only four articles reported the effect of environmental factors on neonatal physiology.

Conclusions: This review highlights the presence of environmental factors, particularly noise and vibration, during transport and raises concerns about their impact on neonates. Although diverse clinical parameters were documented, the small sample sizes and variability in measurement methods across studies limit the ability to draw definitive conclusions. These observations emphasise the need for standardised monitoring protocols and further research to optimise neonatal transport practices.

Keywords: Health services research; Neonatology; Technology.

Figure 1. PRISMA flow diagram showing the selection process for included studies. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.