Effects of Music Genres Reflecting Maternal Listening Preferences During Pregnancy on Distress Markers in Italian Preterm Infants

: Objective: This pilot study aimed to explore how a receptive music intervention, based on musical genres reflecting maternal listening preferences during pregnancy, affects distress levels in Italian preterm infants. Specifically, it investigated the effects of soft pop/rock music, compared with classical music, on infants' LF/HF ratio (derived from heart rate variability [HRV]) and peripheral oxygen saturation (SpO2), which were used as physiological markers of distress. Method: This retrospective observational pilot study analyzed clinical data routinely collected between May 2014 and January 2015 from 27 preterm infants (gestational age 23-32 weeks; birth weight < 1500 g) who received receptive music therapy as part of standard family-centered care in the NICU. Maternal listening preferences during pregnancy were assessed in 30 mothers via an ad hoc questionnaire; a content analysis identified, at the group level, the three most frequently reported artists (i.e., Jovanotti, Vasco Rossi, and W. A. Mozart), which were used to create three standardized playlists. According to the internal clinical procedure, each infant underwent four sessions on consecutive days: a no-music condition on Day 1, followed by the three music conditions on Days 2-4 in randomized order. The LF/HF ratio and SpO2 were measured at five time points per session (one pre-test, three intra-session time points, and one post-test). Wilcoxon signed-rank tests were used to compare conditions and time points, with effect sizes and a Benjamini-Hochberg (FDR) correction for multiple comparisons. Results: The LF/HF ratio did not differ significantly across music conditions or relative to the no-music condition. SpO2 was higher during the Mozart condition than during the no-music condition at three of the five time points; this association remained significant after FDR correction, with medium-to-large effect sizes. No effect was observed for the soft pop/rock conditions on physiological indexes. Conclusions: Receptive music therapy based on maternal listening during pregnancy was not associated with changes in the LF/HF ratio. The Mozart condition was associated with higher SpO2 than the no-music condition. Given the small sample, the single-center setting, and the retrospective observational design, these findings are preliminary and require confirmation in larger, adequately powered prospective trials. Future studies should also examine the specific musical features (e.g., tempo, harmonic structure, voice timbre) that may drive these physiological responses.