Maternal Voice and Infant Sleep in the Neonatal Intensive Care Unit

The effect of maternal voice and non-nutritional sucking on repeated procedural pain of heel prick in neonates: a quasi-experimental study

BACKGROUND

Neonates in the neonatal intensive care unit undergo frequent painful procedures. It is essential to reduce pain using safe and feasible methods.

PURPOSE

To evaluate the effects of non-nutritional sucking, mother's voice, or non-nutritional sucking combined with mother's voice on repeated procedural pain in hospitalized neonates.

METHODS

A quasi-experimental study was conducted in which 141 neonates were selected in a hospital in Changsha, China. Newborns were divided into four groups: non-nutritional sucking (NNS) (n = 35), maternal voice (MV) (n = 35), NNS + MV (n = 34), and control (n = 37) groups. The Preterm Infant Pain Profile-Revised Scale (PIPP-R) was used to assess pain.

RESULTS

During the heel prick, the heart rate value and blood oxygen saturation were significantly different between the groups (P < 0.05). Both non-nutritional sucking and maternal voice significantly reduced PIPP-R pain scores of hospitalized newborns (P < 0.05). The pain-relief effect was more robust in the combined group than in other groups.

CONCLUSIONS

This study showed that both non-nutritional sucking and the mother's voice alleviated repeated procedural pain in neonates. Therefore, these interventions can be used as alternatives to reduce repeated procedural pain.

Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series)

The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.

Race and Ethnicity of Infants Enrolled in Neonatal Clinical Trials: A Systematic Review

Importance

Representativeness of populations within neonatal clinical trials is crucial to moving the field forward. Although racial and ethnic disparities in research inclusion are well documented in other fields, they are poorly described within neonatology.

Objective

To describe the race and ethnicity of infants included in a sample of recent US neonatal clinical trials and the variability in this reporting.

Evidence Review

A systematic search of US neonatal clinical trials entered into Cochrane CENTRAL 2017 to 2021 was conducted. Two individuals performed inclusion determination, data extraction, and quality assessment independently with discrepancies adjudicated by consensus.

Findings

Of 120 studies with 14 479 participants that met the inclusion criteria, 75 (62.5%) included any participant race or ethnicity data. In the studies that reported race and ethnicity, the median (IQR) percentage of participants of each background were 0% (0%-1%) Asian, 26% (9%-42%) Black, 3% (0%-12%) Hispanic, 0% (0%-0%) Indigenous (eg, Alaska Native, American Indian, and Native Hawaiian), 0% (0%-0%) multiple races, 57% (30%-68%) White, and 7% (1%-21%) other race or ethnicity. Asian, Black, Hispanic, and Indigenous participants were underrepresented, while White participants were overrepresented compared with a reference sample of the US clinical neonatal intensive care unit (NICU) population from the Vermont Oxford Network. Many participants were labeled as other race or ethnicity without adequate description. There was substantial variability in terms and methods of reporting race and ethnicity data. Geographic representation was heavily skewed toward the Northeast, with nearly one-quarter of states unrepresented.

Conclusions and Relevance

These findings suggest that neonatal research may perpetuate inequities by underrepresenting Asian, Black, Hispanic, and Indigenous neonates in clinical trials. Studies varied in documentation of race and ethnicity, and there was regional variation in the sites included. Based on these findings, funders and clinical trialists are advised to consider a 3-point targeted approach to address these issues: prioritize identifying ways to increase diversity in neonatal clinical trial participation, agree on a standardized method to report race and ethnicity among neonatal clinical trial participants, and prioritize the inclusion of participants from all regions of the US in neonatal clinical trials.

Language Exposure for Preterm Infants is Reduced Relative to Fetuses

OBJECTIVE

To assess changes and deficits in language and auditory exposures consequent to preterm birth and neonatal intensive care unit stay compared with exposures in utero among typically developing fetuses.

STUDY DESIGN

We analyzed over 23 000 hours of auditory exposure data in a cohort study of 27 typically-developing fetuses and 24 preterm infants. Extrauterine exposures for fetuses were captured by having pregnant women wear 24-hour audio recording devices. For preterm infants, recording devices were placed in the infant's crib. Multilevel linear regressions were conducted to test for group differences and effects of infant sex, maternal education, and mother' occupation. A linear mixed-effects model was used to test for an effect of speaker gender.

RESULTS

Fetuses were exposed to an estimated 2.6 ± 1.8 hours/day of nearby, predominantly female language, nearly 5 times greater than 32 ± 12 minutes/day estimated for preterm infants (P < .001). Preterm infants had greater daily exposure to electronic sounds (5.1 ± 2.5 vs 1.3 ± 0.6 hours; P < .001) and noise (4.4 ± 2.1 vs 2.9 ± 2.8 hours; P < .05), with 4.7 ± 3.9 hours/day of silence. Language and extrauterine sound exposure for fetuses showed a marked day/night cyclical pattern, with low exposure during nighttime hours, but preterm infants' exposures showed significantly less change across the 24-hour cycle (P < .001). Maternal occupation requiring frequent communication predicted greater language exposure (P < .05).

CONCLUSIONS

Our findings provide the first comparison of preterm infant auditory exposures to typically-developing fetuses. Some preterm infants may incur deficits of over 150 hours of language exposure over the preterm period. Given known effects of prenatal/preterm language exposure on neurobehavioral outcomes, this magnitude of deficit is alarming.

Effect of Yakson touch and mother's voice on pain and comfort level during nasal CPAP application in Turkey: A randomized controlled study

PURPOSE

This study was conducted to evaluate the effects of Yakson touch and mother's voice on pain and comfort levels of preterm infants during nasal CPAP application.

DESIGN AND METHODS

The study was conducted as a randomized experimental study with a control group. It included 124 premature infants (mother's voice group = 31, Yakson touch group = 31, mother's voice+ Yakson touch group= 31, control group = 31) of 28-37 weeks of age who had nasal CPAP application in the NICU of a state hospital in souteastern Turkey between April 2019 and August 2020. While the infants in the experimental group received mother's voice, Yakson touch, and mother's voice+ Yakson touch procedures before, during and after nasal CPAP application, the infants in the control group received nasal CPAP application without extra intervention. "Newborn Infant Pain Scale (NIPS)" and "Premature Infant Comfort Scale (PICS)" were used to collect data.

RESULTS

Further analysis revealed that the Yakson Touch was the most beneficial intervention for reducing NIPS scores and PICS scores during and after nasal CPAP application in the experimental groups, followed by mother's voice + Yakson touch and lastly mother's voice.

CONCLUSION

Yakson touch and mother's voice+Yakson touch methods, are effective in neonatal pain and comfort management during and after the nasal CPAP application.

Maternal voice reduces procedural pain in neonates: A meta-analysis of randomized controlled trials

BACKGROUND

Procedural pain management is a very important part in the clinical care of neonates. We aimed to conduct a meta-analysis to evaluate the effects of maternal voice on neonatal procedural pain, to provide insights to the clinical pain care of neonates.

METHODS

Two researchers independently searched PubMed, EMBASE, The Cochrane Library, CINAHL, Web of Science, China Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang and Weipu Database for randomized controlled trials (RCTs) involving the effects of maternal voice on the procedural pain of neonates up to October 25, 2022. Two investigators screened the literature based on the inclusion and exclusion criteria and evaluated the methodological quality of the inclusion study. RevMan 5.3 software was used for the meta-analysis.

RESULTS

A total of 8 RCTs with a total of 584 neonates were included. Our meta-analysis indicated that maternal voice reduces the pain score (SMD = -0.60, 95% CI: -0.81 to -0.39) and heart rate (SMD = -0.81, 95% CI: -1.44 to -0.18) and increases the comfort level (SMD = -0.47, 95% CI: -0.83 to -0.11) and blood oxygen saturation (SMD = 0.70, 95% CI: 0.03-1.38) during procedure (all P < .05). Moreover, maternal voice reduces the pain score (SMD = -0.58, 95% CI: -0.88 to -0.28) and heart rate (SMD = -0.44, 95% CI: -0.75 to -0.12) and increases the blood oxygen saturation (SMD = 0.41, 95% CI: 0.00 to -0.82) after procedure (all P < .05). No publication biases were detected by the funnel plots and Egger tests (all P > .05).

CONCLUSION

Maternal voice is beneficial to reduce procedural pain and improve the physiological indicators in neonates. It is still necessary to conduct high-quality, large sample studies in the future to further elucidate the effect of maternal voice on neonatal pain care.

Effect of maternal voice on proportion of oral feeding in preterm infants

OBJECTIVE

To determine the impact of maternal voice exposure on oral feeding in preterm infants.

STUDY DESIGN

Prospective, unblinded, 2-center intervention study of infants born 28 0/7-34 6/7 weeks gestation. Infants were exposed twice daily to maternal voice for 20 min before attempting oral feeding. Feedings were divided into groups consisting of Baseline, Intervention, and Follow-up feeds. The study was registered at clinicaltrials.gov (NCT05181020).

RESULT

29/37 (78%) mother-infant dyads consented for the study. 25 infants with 2051 feedings were included. Compared to the preceding Baseline, Intervention feeds were associated with an adjusted 7.1 percentage-point increase in oral intake (p = 0.036) and in post-hoc analysis a 71% increased likelihood of having the highest feeding readiness score (p = 0.003).

CONCLUSION

Exposure to maternal voice prior to enteral feeding is feasible and was associated with significantly improved oral feeding proportions in preterm infants.

CLINICAL TRIAL REGISTRY

clinicaltrials.gov (NCT05181020).

NeoConnect: The Design, Implementation, and Impact of a Virtual Family-Centered NICU Program

BACKGROUND

Familial involvement in the neonatal intensive care unit (NICU) reduces parental stress and strengthens parental-infant bonding. However, parents often face barriers to in-person visitation. The coronavirus disease-2019 COVID-19 pandemic has exacerbated limitations to parental bedside presence.

OBJECTIVE

To design, implement, and evaluate a technology-based program to connect NICU babies with their families during the COVID-19 pandemic.

METHODS

We created NeoConnect at our level IV NICU, which included parental audio recordings and video chats between parents and their babies. Parental and NICU staff input on NeoConnect was gathered via preimplementation surveys. Inaugural families and staff members completed a postparticipation survey.

RESULTS

Prior to implementation, all parents who were surveyed (n = 24) wished they could be more involved in their baby's care. In the first 3 months of NeoConnect, 48 families participated in the audio recording project and 14 families participated in the video chat initiative. Following implementation, 85% of surveyed staff (28/33) reported that the patients became calmer when listening to their parents' recorded voice and 100% of surveyed parents (6/6) reported that video chats reduced their stress level.

CONCLUSION

Harnessing technology as a tool to increase parental involvement in the NICU is feasible and beneficial for NICU patients and their families.

Noise in a Neonatal Intensive Care Unit: Exploring Its State and Solutions

BACKGROUND

Concerns regarding the environmental noise issue in neonatal units and an interest in developing strategies to reduce this noise have motivated researchers to conduct comprehensive qualitative research to elucidate the current situation and help improve it.

PURPOSE

This study aims to explore the current state of noise and possible solutions in a neonatal intensive care unit (NICU) in Konya, Turkey.

METHODS

In 2021, a descriptive exploratory study was conducted with a qualitative content analysis approach. Eighteen nurses, three physicians, seven staff members, and four mothers were selected to participate in the study via purposeful sampling. The data were collected from two semi-structured interviews, six focus groups, six observations, and sound source level measurements using a sound decibel meter. Qualitative content analysis was used to analyze the data.

RESULTS

Three main themes and seven major categories emerged from the data analysis. The themes were overt and covert sources, pan-negative effects, and holistic modification. All recorded sound levels exceeded the recommended noise level of 45 dB. Fifty-seven percent of sound sources were in the range of 45-65 dB, and 43% were higher than 65 dB.

IMPLICATIONS FOR PRACTICE AND RESEARCH

This study showed that NICU has a noisy environment with hidden sound sources that can negatively affect all people. This situation must be approached seriously by holistic modification involving environmental modification, behavioral modification, and resource management. It highlighted that each environment is unique and needs to be carefully evaluated to find a suitable and cost-effective solution.

Sensory stimulation for apnoea mitigation in preterm infants

Apnoea, a pause in respiration, is ubiquitous in preterm infants and are often associated with physiological instability, which may lead to longer-term adverse neurodevelopmental consequences. Despite current therapies aimed at reducing the apnoea burden, preterm infants continue to exhibit apnoeic events throughout their hospital admission. Bedside staff are frequently required to manually intervene with different forms of stimuli, with the aim of re-establishing respiratory cadence and minimizing the physiological impact of each apnoeic event. Such a reactive approach makes apnoea and its associated adverse consequences inevitable and places a heavy reliance on human intervention. Different approaches to improving apnoea management in preterm infants have been investigated, including the use of various sensory stimuli. Despite studies reporting sensory stimuli of various forms to have potential in reducing apnoea frequency, non-invasive intermittent positive pressure ventilation is the only automated stimulus currently used in the clinical setting for infants with persistent apnoeic events. We find that the development of automated closed-looped sensory stimulation systems for apnoea mitigation in preterm infants receiving non-invasive respiratory support is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form. IMPACT: This review examines the effects of various forms of sensory stimulation on apnoea mitigation in preterm infants, namely localized tactile, generalized kinesthetic, airway pressure, auditory, and olfactory stimulations. Amongst the 31 studies reviewed, each form of sensory stimulation showed some positive effects, although the findings were not definitive and comparative studies were lacking. We find that the development of automated closed-loop sensory stimulation systems for apnoea mitigation is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form.

Lateralized neonatal EEG coherence during sleep predicts language outcome

BACKGROUND

Enriched language exposure may benefit infants in the neonatal intensive care unit. We hypothesized that changes in neonatal electroencephalogram (EEG) coherence during sleep, in response to maternal voice exposure, predict language development.

METHODS

Convalescent neonates underwent 12-h polysomnography. A recording of the mother's voice was randomized to continuous playback in the first or second 6 h. We calculated the imaginary coherence (ICOH-a measure of functional connectivity) between EEG leads. Spearman correlations were computed between ICOH and 18-month Bayley-III language scores.

RESULTS

Thirty-five neonates were included (N = 18 33-to-<35 weeks gestation; N = 17 ≥ 35 weeks). Predictive value of ICOH during neonatal non-rapid eye movement (NREM) sleep was left lateralized, and varied with gestational age and voice playback. ICOH in the left-hemispheric (C3-Cz; T3-Cz) channels across multiple EEG frequency bands was associated with 18-month language scores (rho = -0.34 to -0.48). The association was driven by neonates born at 33-34 weeks gestation, and a trend suggested a possible effect of maternal voice at some EEG frequencies. Right hemisphere ICOH (C4-Cz; T4-Cz) was not associated with language outcome.

CONCLUSIONS

Left-hemispheric EEG functional connectivity during neonatal NREM sleep shows early signs of physiologic asymmetry that may predict language development. We speculate that sleep analyses could have unique prognostic value.

IMPACT

During neonatal NREM sleep, EEG functional connectivity predicts future language development. Left temporal and central EEG coherence-specifically the imaginary component of coherence-is predictive, whereas the same analysis from the right hemisphere is not. These results appear to vary according to the infant's gestational age, and a trend suggests they may be enhanced by measuring functional connectivity during exposure to the mother's voice. These findings identify early evidence of physiologic differentiation within the cerebral hemispheres and raise the possibility that neonatal NREM sleep has a role to play in language development.

Early development of sleep and brain functional connectivity in term-born and preterm infants

The proper development of sleep and sleep-wake rhythms during early neonatal life is crucial to lifelong neurological well-being. Recent data suggests that infants who have poor quality sleep demonstrate a risk for impaired neurocognitive outcomes. Sleep ontogenesis is a complex process, whereby alternations between rudimentary brain states-active vs. wake and active sleep vs. quiet sleep-mature during the last trimester of pregnancy. If the infant is born preterm, much of this process occurs in the neonatal intensive care unit, where environmental conditions might interfere with sleep. Functional brain connectivity (FC), which reflects the brain's ability to process and integrate information, may become impaired, with ensuing risks of compromised neurodevelopment. However, the specific mechanisms linking sleep ontogenesis to the emergence of FC are poorly understood and have received little investigation, mainly due to the challenges of studying causal links between developmental phenomena and assessing FC in newborn infants. Recent advancements in infant neuromonitoring and neuroimaging strategies will allow for the design of interventions to improve infant sleep quality and quantity. This review discusses how sleep and FC develop in early life, the dynamic relationship between sleep, preterm birth, and FC, and the challenges associated with understanding these processes. IMPACT: Sleep in early life is essential for proper functional brain development, which is essential for the brain to integrate and process information. This process may be impaired in infants born preterm. The connection between preterm birth, early development of brain functional connectivity, and sleep is poorly understood. This review discusses how sleep and brain functional connectivity develop in early life, how these processes might become impaired, and the challenges associated with understanding these processes. Potential solutions to these challenges are presented to provide direction for future research.

Parental Book-Reading to Preterm Born Infants in NICU: The Effects on Language Development in the First Two Years

Background: After preterm birth, infants are at high risk for delays in language development. A promising intervention to reduce this risk is represented by the exposure to parental voices through book-reading in Neonatal Intensive Care Units (NICU). This study investigated the possible advantages of book-reading to preterm neonates during their NICU stay on their subsequent language development. Methods: 100 families of preterm infants were recruited. The parents of 55 preterm infants (Reading Group) received a colored picture-book on NICU admission and were supported to read to their neonate as often as possible and to continue after hospital discharge. Forty-five infants (Control Group) were recruited before the beginning of the intervention. Infant language development was assessed with the Hearing and Language quotients of the Griffith Mental Development Scale at the corrected ages of 3, 6, 9, 12, 18 and 24 months. Results: Regardless of group membership, Hearing and Language mean quotients decreased between 9 and 18 months; nevertheless, this decrease was considerably reduced in the Reading group, compared to the Control Group. Conclusions: Reading in NICUs represents a suitable intervention that could positively influence language development and parent-infant relationships in preterm children. The study findings support its implementation as a preventive measure.

Proposing a care practice bundle for neonatal encephalopathy during therapeutic hypothermia

Neonates with neonatal encephalopathy (NE) often present with multi-organ dysfunction that requires multidisciplinary specialized management. Care of the neonate with NE is thus complex with interaction between the brain and various organ systems. Illness severity during the first days of birth, and not only during the initial hypoxia-ischemia event, is a significant predictor of adverse outcomes in neonates with NE treated with therapeutic hypothermia (TH). We thus propose a care practice bundle dedicated to support the injured neonatal brain that is based on the current best evidence for each organ system. The impact of using such bundle on outcomes in NE remains to be demonstrated.

Assessment of Sleep-Related Problems in Children with Cerebral Palsy Using the SNAKE Sleep Questionnaire

Cerebral palsy (CP) represents the most common motor impairment in childhood. The presence of sleep problems has not yet been investigated with an instrument specifically designed for this population. In this hospital-based, prospective study, N = 100 children (M = 7.9, range: 2-18 years) with CP were included. All patients underwent pediatric neurologists' screening incorporating instruments (Data Collection Form; Gross Motor Functions Classification System, GMFCS; Bimanual Fine Motor Function, BFMF) recommended by the "Surveillance of Cerebral Palsy in Europe (SCPE)". Parents completed the "Sleep Questionnaire for Children with Severe Psychomotor Impairment (SNAKE)". Children's sleep behavior was increasingly conspicuous, with greater gross motor (SNAKE scales: disturbances remaining asleep, daytime sleepiness) and fine motor (additionally SNAKE scale arousal and breathing problems) functional impairment. Overall, a proportion of children showed sleep behavior outside the SNAKE's normal range. No relevant sleep differences were identified between different CP subtypes and comorbidities. Applying a population-specific questionnaire, children's functional impairment seems to be more relevant to their sleep behavior than the CP subtype or CP comorbidities.

Mothers' voices and white noise on premature infants' physiological reactions in a neonatal intensive care unit: A multi-arm randomized controlled trial

BACKGROUND

A few positive effects of mothers' voice on physiological outcomes have been studied and limited studies have focused on the level of cortisol. In addition, white noise has recently been found to be beneficial for human sleep, but studies in premature infants were limited and no study has compared the effects of mothers' voice and white noise on premature infants.

OBJECTIVE

To examine the effects of mothers' voice and white noise on sleep-wake patterns, salivary cortisol levels, weight gain, heart rate, and oxygen saturation of premature infants in a neonatal intensive care unit (NICU).

METHODS

This was a three-group randomized controlled trial. A total of 103 medically stable premature infants in incubators were recruited from the NICU of a women's and children's hospital in China between March and December 2017 and were randomized into three groups: the mothers' voice group (n = 34), the white noise group (n = 34), and the routine care group (n = 35). Mothers' voice, white noise, and no voice were provided to the three groups for 20 min at a time, three times a day for four consecutive days. The sound levels of the mothers' voice and white noise were controlled between 50 and 55 dB. Sleep-wake patterns, salivary cortisol level, and weight were measured at pre-test and post-test whereas heart rate and oxygen saturation were measured every five-minute at 11am, 2pm, 5pm for four-consecutive days.

RESULTS

A group difference was found only in weight gain (p = 0.003), with weight gain in the white noise group being significantly higher than the mothers' voice group (Z=-3.447, p = 0.001). Significant declines in total sleep time and sleep efficiency and increases in wake time after sleep onset and average awakening time were only found in the routine-care group between the pre-test and post-test (p<0.05). No significant differences were found in the salivary cortisol levels, heart rates, and oxygen saturation levels among the three groups (p>0.05). A significant increase in oxygen saturation during the 20-min intervention was found in white noise group. Non-significant decreases in the heart rate during the 20-min intervention and salivary cortisol levels at post test were noted in all the three groups.

CONCLUSION

White noise is more useful for encouraging weight gain in preterm infants compared with mothers' voices. White noise might be introduced for use in the care of premature infants in NICUs, and more high-quality randomized controlled trials are needed to confirm these findings. Trial Registration No: ChiCTR-INR-17012755.

Assessing speech exposure in the NICU: Implications for speech enrichment for preterm infants

OBJECTIVE

Quantify NICU speech exposure over multiple days in relation to NICU care practices.

METHODS

Continuous measures of speech exposure were obtained for preterm infants (n = 21; 12 M) born <34 weeks gestational age in incubators (n = 12) or open cribs (n = 9) for 5-14 days. Periods of care (routine, developmental) and delivery source (family, medical staff, cuddler) were determined through chart review.

RESULTS

Infants spent 13% of their time in Care, with >75% of care time reflecting developmental care. Speech counts were higher during care than no care, for mature vs. immature infants, and for infants in open cribs vs. incubators. Family participation in care ranged widely, with the highest speech counts occurring during periods of intentional voice exposure.

CONCLUSIONS

Care activities represent a small portion of NICU experiences. Speech exposure during Developmental Care, especially with intentional voice exposure, may be an important source of stimulation. Implications for care practices are discussed.