J Korean Acad Child Health Nurs.  2010 Jul;16(3):211-219.

The Effects of Maternal Heart Sound on the Weight, Physiologic Responses and Behavioral States of Premature Infants

• Yeum MK
• Ahn YM
• Seo HS
• Jun YH

Abstract

PURPOSE
The study was done to measure the effects of maternal heart sound on body weight, physiologic reactions (heart rate [HR] and cortisol) and behavioral states of preterm infants.
METHODS
Thirty-five preterm infants were recruited from a neonatal intensive care unit at a university hospital. Institutional Review Board approval and informed consent were obtained. The infants were assigned to an experimental group (n=18) with an auditory stimulation for 7 days of life, a continuous delivery of maternal heart sound using MP3 attached inside the incubator, or to a control (n=17) without any auditory stimulation. The outcome variables, daily variations in weight, HR and behavioral states, and differences in cortisol were analyzed.
RESULTS
There were differences in variations of daily weights (F=3.431, p=.011) and in cortisol (t=3.184, p=.006) between groups, but no difference in variations of daily HR (F=0.331, p=.933) and behavioral states (F=1.842, p=.323).
CONCLUSION
The findings support the safety of continuous maternal heart sound as no changes in HR and behavioral states occurred, and the efficacy as weight increased and cortisol decreased. This auditory simulation may lead to more efficient utilization of energy in preterm infants by consistently providing familiar sounds from intrauterine life and blocking noxious sounds from NICU environments.

Keyword

Premature infants; Acoustic stimulation; Heart sounds; Heart rate; Weight

MeSH Terms

Acoustic Stimulation
Body Weight
Ethics Committees, Research
Heart
Heart Rate
Heart Sounds
Humans
Hydrocortisone
Incubators
Infant
Infant, Newborn
Infant, Premature
Informed Consent
Intensive Care, Neonatal
Weights and Measures
Child Health
Hydrocortisone