Effects of Lullaby Exposure on Pain and Physiological Outcomes in Preterm Infants in Neonatal Intensive Care Units: A Systematic Review and Meta-Analysis

Abstract Background: Preterm infants in neonatal intensive care units (NICUs) are frequently exposed to painful procedures and environmental stressors that may disrupt autonomic regulation and neurodevelopment. Lullaby-based auditory interventions have been proposed as safe, non-pharmacological strategies to reduce pain and improve physiological stability, yet evidence specific to lullabies has not been systematically synthesized.Objective: This review evaluated the effects of lullaby exposure on pain and physiological parameters in preterm infants in NICUs.Methods: A systematic search of PubMed, Scopus, and Cochrane was conducted in accordance with PRISMA guidelines. Randomized controlled trials and quasi-experimental studies involving preterm infants (<37 weeks’ gestation) were included. Lullaby interventions were compared with standard care or other auditory controls. Neonatal pain assessed by the Neonatal Infant Pain Scale (NIPS) was meta-analyzed using a random-effects model, while physiological outcomes were narratively synthesized.Results: Nine studies were included. Meta-analysis showed a non-significant trend toward lower pooled NIPS scores in the lullaby group, with an approximate one-point reduction favoring lullaby exposure. Descriptively, most studies reported significant within-group reductions in pain scores following lullaby interventions, particularly during post-procedural recovery. Maternal voice–based lullabies consistently demonstrated greater analgesic effects than recorded or instrumental lullabies. Physiological outcomes showed generally favorable trends, including more stable heart rates, reduced respiratory rates, and modest improvements in oxygen saturation, especially at delayed post-intervention time points.Conclusion: Lullaby exposure, particularly maternal voice–based interventions, may serve as a safe and feasible adjunct to non-pharmacological pain management in NICUs, supporting short-term pain relief and physiological regulation in preterm infants.