Impact of spontaneous versus expressive maternal singing on physiological parameters and regional tissue oxygenation in preterm infants: a prospective cross-over study.

BACKGROUND AND AIM: Preterm birth and subsequent NICU hospitalization poses major challenges on maternal-infant bond and expose neonates to environmental stressors. Auditory stimulation with maternal singing has shown potential benefits on infants' development and physiological stability. We aimed to evaluate the effects of two different maternal singing modalities-spontaneous and expressive-on physiological parameters and regional tissue oxygenation in stable preterm infants. METHODS: Twenty mother-infant dyads were enrolled. Heart rate (HR), peripheral oxygen saturation (SpO2), cerebral (CrSO2) and splanchnic oxygenation (SrSO2), as well as cerebral (cFTOE) and splanchnic fractional tissue oxygen extraction (sFTOE), were continuously monitored using pulse oximetry combined with near-infrared spectroscopy (NIRS) during a 40-min period (10 min baseline, 20 min auditory stimulation, 10 min post-stimulation), during which both spontaneous and expressive maternal singing were administered. Variations from baseline in the study parameters during each maternal singing modality and in the post-stimulation phase were analysed using repeated-measures linear mixed-effects models. RESULTS: Expressive maternal singing induced a significant CrSO2 increase (p = 0.031) and a corresponding cFTOE reduction (p = 0.032) compared to baseline, while no significant difference in HR, SpO2, SrSO2 and sFTOE was observed. These effects persisted in the post-administration phase (CrSO2, p = 0.028; cFTOE p = 0.005). No significant changes were observed during the administration of spontaneous maternal singing. CONCLUSION: Expressive maternal singing promotes cerebral metabolic well-being in preterm infants, independently of systemic hemodynamic changes. These preliminary findings may support the integration of structured music therapy interventions with maternal involvement in neonatal developmental care.