Weight gain velocity in very low-birth-weight infants: effects of exposure to biological maternal sounds.

Objective: To examine the effects of biological maternal sounds (BMS) on weight gain velocity in very low-birth-weight (VLBW) infants (≤ 1,500 g).

Study Design: An exploratory study with a matched-control design. A prospective cohort of VLBW infants exposed to attenuated recordings of BMS during their neonatal intensive care unit hospitalization were compared with retrospective controls matched 1:1 for sex, birth weight, gestational age, scores for neonatal acute physiology and perinatal extension (SNAPPE - II) scores (n = 32).

Results: A linear mixed model controlling for gestational age, chronic lung disease, and days to regain birth weight revealed that infants receiving BMS significantly improved their weight gain velocity compared matched controls (p < 0.001) during the neonatal period. No differences were found on days spent nothing by mouth (p = 0.18), days until full enteral feeds (p = 0.51), total fluid intake (p = 0.93), or caloric intake (p = 0.73).

Conclusion: Exposure to BMS may improve weight gain velocity in VLBW infants. Further research is needed to evaluate the effectiveness of this noninvasive intervention during the neonatal period.