Background
Mother's voice exposure is an important contributor to development of preterm infants. The benefits include decreased apnea and bradycardia episodes, a bigger auditory cortex and improved cognitive development at 2 years of age. Oral feeding is one of the primary functions of the infants brain and achievement of full oral feedings is associated with decreased length of hospital stay and other improved neonatal outcomes. We proposed to examine the association between exposure to mother's voice prior to enteral feeding and oral feeding volume and rate in preterm infants. We present here the preliminary feasibility results of this prospective study conducted at a level III and IV neonatal intensive care units (NICU) simultaneously.
Objective
To determine if exposure to 20 minutes of mother's voice before feeds and continuing during feeds can be accomplished in a consistent, systematic manner for 2 feeds per day.
Methods
We prospectively studied infants born between 6/01/2020 and 9/30/2020 with gestational age between 28 0/7 and 34 6/7 weeks to English speaking and ≥18 year old mothers. Infants included in the study were taking a daily oral intake of <50% of full enteral feeds during the first 2 days prior to the initiation of protocol.
Institutional Review Board approval was obtained. All NICU staff were provided in-service on the study protocol. Informed consent was obtained from eligible infant mothers after admission to the NICU. Infants enrolled in the study heard mothers voice twice a day as a recording or live for at least 20 minutes prior to enteral feedings. Individual mother's voice reading children's stories was recorded with Voicememos application on IPad (Apple Inc. Cupertino, CA). These recordings were played via the Ipad or Kindle on Bluetooth WavHello SoundBub speakers (WavHello Inc., Los Angeles, CA).
Results
Of the 28 infant's mothers approached, 21 (75%) were consented, while 7 (25%) declined to participate in the study. The mean gestational age and birth weight of the infants in our study was 32 weeks (SD=1.5) and 1773 grams (SD=342), respectively. 65% of the infants were male. Out of the 21 consented infants, 17 (80%) completed the study and 1 (5%) infant took >50% feeds orally in the first 2 days. The attrition rate was 3 (15%); 1 (5%) mother was uncomfortable recording her voice and 2 (10%) infants had technical problems with the recordings. Of 421 total possible mothers voice exposures, 380 (90%) occurred and 41 (10%) were missed. Of the recordings played, 11 (3%) were for a duration of less than 20 minutes.
Conclusion
The high consent and study completion rates showed that parents of preterm infants are interested in participating in prospective studies related to mother's voice exposure and feeding. The high rate of mother's voice exposure suggests a larger multicenter randomized control trial is feasible using a similar study design such as ours with limited resources and budget.
