The effect of prenatal music therapy on fetal and neonatal status: A systematic review and meta-analysis

Effects of recorded maternal voice on anthropometric parameters and heart rate in premature infants: A pilot randomised controlled trial

PURPOSE

To explore the benefits of a recorded maternal voice intervention on weight, recumbent length, head circumference, and heart rate of preterm infants in the neonatal intensive care unit.

METHODS

A pilot randomised controlled trial was conducted in this study. Preterm infants in the neonatal intensive care unit (N = 109) were recruited and randomly assigned to an intervention or control group. Both groups received routine nursing care, while preterm infants in the intervention group received a recorded maternal voice program of 20 min, twice daily for 21 days. Preterm infants' daily weight, recumbent length, head circumference, and heart rate were collected during the 21-day intervention. Participants' heart rate in the intervention group was also recorded once a day pre-during-after the recorded maternal voice program.

RESULTS

Preterm infants in the intervention group showed a significant increase in weight (-75.94, 95% CI -108.04, -43.85, P < 0.001), recumbent length (-0.54, 95% CI -0.76, -0.32, P < 0.001), and head circumference (-0.37, 95%CI -0.56, -0.18, P < 0.001) compared with the control group. Preterm infants in the intervention group also showed significant changes in heart rate pre-during-after the recorded maternal voice program. However, no significant differences were found in the heart rate scores between the two groups.

DISCUSSION

The changes in heart rate pre-during-after the intervention may help explain participants' more significant increase in weight, recumbent length, and head circumference.

PRACTICE IMPLICATIONS

The recorded maternal voice intervention could be incorporated into clinical practice to promote growth and development in preterm infants in the neonatal intensive care unit.

STUDY REGISTRATION

Australian New Zealand Clinical Trials Register, https://www.anzctr.org.au/; (registration number: ACTRN12622000019707).

Prenatal daily musical exposure is associated with enhanced neural representation of speech fundamental frequency: Evidence from neonatal frequency-following responses

Fetal hearing experiences shape the linguistic and musical preferences of neonates. From the very first moment after birth, newborns prefer their native language, recognize their mother's voice, and show a greater responsiveness to lullabies presented during pregnancy. Yet, the neural underpinnings of this experience inducing plasticity have remained elusive. Here we recorded the frequency-following response (FFR), an auditory evoked potential elicited to periodic complex sounds, to show that prenatal music exposure is associated to enhanced neural encoding of speech stimuli periodicity, which relates to the perceptual experience of pitch. FFRs were recorded in a sample of 60 healthy neonates born at term and aged 12-72 hours. The sample was divided into two groups according to their prenatal musical exposure (29 daily musically exposed; 31 not-daily musically exposed). Prenatal exposure was assessed retrospectively by a questionnaire in which mothers reported how often they sang or listened to music through loudspeakers during the last trimester of pregnancy. The FFR was recorded to either a /da/ or an /oa/ speech-syllable stimulus. Analyses were centered on stimuli sections of identical duration (113 ms) and fundamental frequency (F0  = 113 Hz). Neural encoding of stimuli periodicity was quantified as the FFR spectral amplitude at the stimulus F0 . Data revealed that newborns exposed daily to music exhibit larger spectral amplitudes at F0 as compared to not-daily musically-exposed newborns, regardless of the eliciting stimulus. Our results suggest that prenatal music exposure facilitates the tuning to human speech fundamental frequency, which may support early language processing and acquisition. RESEARCH HIGHLIGHTS: Frequency-following responses to speech were collected from a sample of neonates prenatally exposed to music daily and compared to neonates not-daily exposed to music. Neonates who experienced daily prenatal music exposure exhibit enhanced frequency-following responses to the periodicity of speech sounds. Prenatal music exposure is associated with a fine-tuned encoding of human speech fundamental frequency, which may facilitate early language processing and acquisition.

The impact of sound stimulations during pregnancy on fetal learning: a systematic review

BACKGROUND

The developing nervous system in utero is exposed to various stimuli with effects that may be carried forward to the neonatal period. This study aims to investigate the effects of sound stimulation (music and speech) on fetal memory and learning, which was assessed later in neonatal period.

METHODS

The MEDLINE (pubmed), Scopus, EMBASE, and Cochrane Library were searched. Two reviewers selected the studies and extracted the data independently. The quality of eligible studies was assessed using The Joanna Briggs Institute Critical Appraisal Checklist for Randomized Controlled Trials (RCTs).

RESULTS

Overall 3930 articles were retrieved and eight studies met the inclusion criteria. All of the included studies had good general quality; however, high risk of selection and detection bias was detected in most of them. Fetal learning was examined through neonatal electrocardiography (ECG), electroencephalography (EEG), habituation tests, and behavioral responses. Seven studies showed that the infants had learned the fetal sound stimulus and one study indicated that the prenatally stimulated infants performed significantly better on a neonatal behavior test. There was considerable diversity among studies in terms of sound stimulation type, characteristics (intensity and frequency), and duration, as well as outcome assessment methods.

CONCLUSIONS

Prenatal sound stimulation including music and speech can form stimulus-specific memory traces during fetal period and effect neonatal neural system. Further studies with precisely designed methodologies that follow safety recommendations, are needed.

Effect of Musical Stimulation on Placental Programming and Neurodevelopment Outcome of Preterm Infants: A Systematic Review

BACKGROUND

The fetal environment is modulated by the placenta, which integrates and transduces information from the maternal environment to the fetal developmental program and adapts rapidly to changes through epigenetic mechanisms that respond to internal (hereditary) and external (environmental and social) signals. Consequently, the fetus corrects the trajectory of own development. During the last trimester of gestation, plasticity shapes the fetal brain, and prematurity can alter the typical developmental trajectories. In this period, prevention through activity-inducing (e.g., music stimulation) interventions are currently tested. The purpose of this review is to describe the potentialities of music exposure on fetus, and on preterm newborns in the Neonatal Intensive Care Unit evaluating its influence on neurobehavioral development.

METHODS

Databases were searched from 2010 to 2022 for studies investigating mechanisms of placental epigenetic regulation and effects of music exposure on the fetus and pre-term neonates.

RESULTS

In this case, 28 selected papers were distributed into three research lines: studies on placental epigenetic regulation (13 papers), experimental studies of music stimulation on fetus or newborns (6 papers), and clinical studies on premature babies (9 papers). Placental epigenetic changes of the genes involved in the cortisol and serotonin response resulted associated with different neurobehavioral phenotypes in newborns. Prenatal music stimulation had positive effects on fetus, newborn, and pregnant mother while post-natal exposure affected the neurodevelopment of the preterm infants and parental interaction.

CONCLUSIONS

The results testify the relevance of environmental stimuli for brain development during the pre- and perinatal periods and the beneficial effects of musical stimulation that can handle the fetal programming and the main neurobehavioral disorders.