For babies, maternal voice can not only make them laugh but also can alleviate their pain.
A study by the College of Nursing, National Yang Ming Chiao Tung University (NYCU) on heel sticks in preterm infants discovered that during the heel sticks and blood draw process, if preterm infants hear maternal voices, their heart rate is more stable, and their external pain response is more subdued.
Out of considerations for withdrawing blood for blood tests and the risk of bleeding, a common blood draw technique used in infants is heel sticks. This technique involves stabbing infants’ heels using needles to obtain their health information. However, the pain caused by this intrusive examination method has negative impacts on preterm infants and worries the mother.
To verify the criticalness of maternal voice on infants, Prof. Chi-Wen Chen of the College of Nursing, NYCU led a research team and Ms. Wan-Chin Yu, who was a registered nurse at the neonatal intensive care unit at Chang Gung Memorial Hospital, Taoyuan to conduct an experiment. In the experiment, 64 preterm infants were randomly divided into the experimental group and the control group. On the fourth day after birth, the preterm infants of the experimental group received heel sticks. Three minutes before receiving heel sticks, a recording from their mother reading the children’s book Xiaoqi’s Yellow Persimmon was played at no louder than 70 dB until the entire blood draw process ended. The infants’ pain reactions were measured by six behavioral indicators including facial expression, crying, breathing pattern, arms, legs, and state of arousal. The results revealed that playing maternal sound significantly reduced the heart rate and pain indicators of participants in the experimental group compared to those of the control group.
In addition, the research team discovered that infants who listened to maternal voices had slower respiratory rate, increased blood oxygen saturation, and superior mother–infant bonding. Although the data of these three indicators did not show significant differences, the experimental group indeed has better data performance..
A past French study revealed that playing recordings of mothers reading the classic The Little Prince is conducive to stabilizing infants’ heart rate and reducing infants’ sense of insecurity from not having their mothers by their side. However, the effects were related to the volume of the maternal voice. When the recording exceeds 70 dB, infants’ heart rate increased rather than decreased, reflecting that loud sounds are not conducive to soothing infants.
Prof. Chen stated that preterm infants require medical care at a high frequency for a long time. Limited by the ward space and visiting hours, mothers cannot stay by the infants all the time. Pain is not only a physiological feeling but also affects infants’ behavioral reactions.
Ms. Yu stated that the results of this study confirmed the effect of maternal voice on infants and showed that when clinical nurses care for preterm infants, specifically, when they perform heel sticks, they should consider incorporating more measures friendly to mothers and infants. For example, they can provide a more diverse environment for the preterm infants, and clinically, they can provide a family-centered novel care model.
This study was jointly conducted by NYCU and Chang Gung Memorial Hospital, Taoyuan. The results of this study have been published in the Journal of Pediatric Nursing.