Inflammatory mediators of stress exposure and neurodevelopment in very preterm infants: Protocol for the stress neuro-immune study

DNA Methylation, Inflammation, and Neurobehavior in Preterm Infants

Objectives: Inflammation contributes to disparate neurodevelopmental outcomes between preterm and term-born infants. In this context, DNA methylation may contribute to inflammation by affecting gene expression. Brain-derived neurotrophic factor (BDNF) and nuclear factor-kappa-B-inhibitor alpha (NFKBIA) are important genes for targeted DNA methylation analysis. The aims of this study were to (1) identify associations between inflammatory factors and BDNF and NFKBIA methylation, and (2) identify associations between BDNF and NFKBIA methylation and early neurobehavior in preterm infants. Methods: In a longitudinal cohort study of preterm infants born 28-31 weeks gestational age, blood samples were collected weekly for the quantification of inflammatory factors. We extracted DNA from saliva samples and quantified methylation of six BDNF cytosine-phosphate-guanine (CpG) sites and five NFKBIA CpG sites. Neurobehavior was assessed using the Neurobehavioral Assessment of the Preterm Infant. Results: Sixty-five infants were included in the analysis. In females, inflammatory factors were positively associated with BDNF methylation of most CpG sites. Interleukin-1 receptor antagonist was negatively associated with NFKBIA methylation at two CpG sites. In males, interleukin-6 was negatively associated with BDNF and NFKBIA methylation at most CpG sites. In females, BDNF methylation at two sites was inversely associated with motor performance. In males, NFKBIA methylation at one site was inversely associated with motor performance. Conclusion: This study provides evidence for the relationship between inflammation and neurobehavior in preterm infants, working mechanistically through DNA methylation. The finding of a difference between males and females suggests that female infants are potentially more vulnerable to inflammation and warrants future study.

Predictors of Stress Exposure in Hospitalized Preterm Infants

BACKGROUND

Stress exposure in the neonatal intensive care unit (NICU) is associated with poor outcomes in preterm infants. However, factors predicting subsequent NICU stress exposure have not been identified.

PURPOSE

To characterize NICU stressors experienced by preterm infants during the first 2 weeks of life and identify demographic, perinatal, and institutional variables associated with stress exposure.

METHODS

A secondary analysis of data from a nonexperimental, prospective study was conducted using data from 60 very preterm infants born 28 to 31 weeks gestational age. Stress exposures during the first 2 weeks of life, operationalized as number of invasive procedures, were characterized by type and quantity for each infant using data extracted from electronic health records. Associations between number of invasive procedures and demographic, perinatal, or institutional variables were analyzed using linear regressions with robust standard errors.

RESULTS

Preterm infants experienced, on average, 98 (SD = 41.8) invasive procedures. Of these invasive procedures, nasal and/or oral suctioning episodes (58.1%), followed by skin-breaking procedures (32.6%), were most frequent. Differences in the number of invasive procedures were found for maternal race; infants born to Black mothers experienced fewer total invasive procedures than infants born to White mothers. The number of invasive procedures also varied across NICUs.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Preterm infant stress exposure differed by maternal race and NICU, consistent with research findings of differential treatment of diverse infants. Further research is needed to understand the reasons for these differences and to identify best practices to standardize neonatal care.

Midwifery and nursing: Considerations on cord management at birth

Mounting evidence overwhelmingly supports the practice of the return of an infant's placental blood volume at the time of birth. Waiting just a few minutes before clamping the umbilical cord can provide health benefits to infants of all gestational ages. Despite the robust evidence, uptake of delayed cord clamping (DCC) into mainstream obstetrical practice is moving slowly. The practice of DCC is influenced by various factors that include the setting in which the birth takes place, the use of evidence-informed guidelines and other influences that facilitate or hinder the practice of DCC. Through communication, collaboration, and unique disciplinary perspectives, midwives and nurses work with other members of their respective care team to develop strategies for best practice to improve an infant's well-being through optimal cord management. Midwifery has been practiced for centuries throughout the world and midwives have supported DCC since the beginning of recorded history. An important tenet of midwifery philosophy is watchful waiting and non-intervention in normal processes. Nurses are vital to care of birthing families in- and out-of-hospitals as well as in prenatal and postpartum ambulatory care. Nurses and midwives are positioned to be involved in the process of adapting to the mounting evidence for DCC. Strategies to increase better utilization of the practice of DCC have been proposed. For all, teamwork and collaboration among disciplines participating in maternity care are essential for adapting to the new evidence. Involving midwives and nurses as partners in an interdisciplinary approach to plan, implement and sustain DCC at birth increases success.

Efecto de un programa de enfermería sobre los cuidados centrados en el desarrollo del recién nacido prematuro

Objetivo. Determinar el efecto de un programa de enfermería sobre los cuidados centrados en el desarrollo (neurodesarrollo) del recién nacido prematuro (RNPT) en el servicio de cuidados intensivos neonatal del Instituto Nacional Materno Perinatal (INMP) 2021. Materiales y Métodos. Investigación preexperimental, nivel aplicativo y enfoque cuantitativo, población enfermeras asistenciales del servicio de cuidados intensivos neonatal del INMP, muestra constituida por 26 enfermeras. Las técnicas empleadas fueron la observación y la encuesta y dos instrumentos, lista de chequeo (KR 0.792) y escala de Likert (Alfa de Crombach 0.917), aplicados en 2 fases antes y después del programa de intervención. Los datos recolectados fueron procesados con el programa SPSS y para medir el efecto del programa de intervención se empleó la prueba de Mc Nemar. El estudio fue autorizado por la unidad funcional de investigación del Instituto Nacional Materno Perinatal. Resultados. Existe diferencia en las prácticas sobre los cuidados centrados en el desarrollo del RNPT aplicados por las enfermeras del servicio de cuidados intensivos neonatal del INMP, evidenciado por un p=0.031 (p<0.05). Antes del programa de intervención las enfermeras tenían 73.1% de prácticas adecuadas, posterior al programa de intervención las practicas adecuadas incrementaron a 96,2% y las practicas inadecuadas disminuyeron de 26.9% a 3,8%. Conclusiones. El programa de intervención de enfermería sobre los cuidados centrados en el desarrollo en el servicio de cuidados intensivos neonatal del INMP, puede mejorar la efectividad en la atención del RNPT. Hallándose en su mayor porcentaje practicas adecuadas después del programa de intervención.

Early-life factors associated with neurobehavioral outcomes in preterm infants during NICU hospitalization

BACKGROUND

The aim of this study was to investigate the influence of early-life pain/stress and medical characteristics on neurobehavioral outcomes in preterm infants.

METHODS

A prospective cohort study was conducted with 92 preterm infants (28-32 weeks gestational age [GA]). Early-life pain/stress was measured via the Neonatal Infant Stressor Scale (NISS) during the first 28 days of NICU hospitalization. Neurobehavioral outcomes were evaluated using the NICU Network Neurobehavioral Scale at 36-38 weeks post-menstrual age. Functional regression and machine learning models were performed to investigate the predictors of neurobehavioral outcomes.

RESULTS

Infants experienced daily acute pain/stress (24.99 ± 7.13 frequencies) and chronic events (41.13 ± 17.81 h). Up to 12 days after birth, both higher acute and chronic NISS scores were associated with higher stress scores; and higher chronic NISS scores were also related to lower self-regulation and quality of movement. Younger GA predicted worse neurobehavioral outcomes; GA < 31.57 weeks predicted worse stress/abstinence, self-regulation, and excitability; GA < 30.57 weeks predicted poor quality of movement. A higher proportion of maternal breastmilk intake predicted better self-regulation, excitability, and quality of movement in older GA infants.

CONCLUSIONS

Preterm infants are vulnerable to the impact of early-life pain/stress. Neurobehavioral outcomes are positively associated with increased GA and higher maternal breastmilk intake.

IMPACT

During the first 12 days of life, preterm infant neurobehavioral outcomes were vulnerable to the negative impact of acute and chronic pain/stress. Future research is warranted to investigate the long-term effects of early-life pain/stress on neurobehavioral outcomes. Gestational age remains one of the critical factors to predict neurobehavioral outcomes in preterm infants; older gestational age significantly predicted better neurobehavioral outcomes. Feeding with a higher proportion of maternal breastmilk predicted better neurobehavioral outcomes. Future research is warranted to investigate how maternal breastmilk may buffer the negative effects of early-life pain/stress on neurobehavioral outcomes.

Conducting Neonatal Intensive Care Unit Research During a Pandemic: Challenges and Lessons Learned

BACKGROUND

The coronavirus pandemic disrupted normal clinical operations and research. Nurse scientists conducting research studies in the neonatal intensive care unit experienced significant challenges to continuing their research studies amid national lockdowns and hospital visitation restrictions.

OBJECTIVES

The purpose of this article is to describe the challenges encountered by nurse scientists conducting research studies in the neonatal intensive care unit during the pandemic, the creative solutions devised to overcome these barriers, and the lessons learned during this unprecedented time.

METHODS

Using our pandemic area studies as exemplars, we highlight the barriers encountered in continuing our research in the intense environment of the neonatal intensive care unit.

RESULTS

Visitor restrictions limited the presence of parents and researchers in the neonatal intensive care unit during the pandemic, causing disruptions to participant recruitment and data collection. Laboratory closures further limited research activities during the pandemic. Strategies to overcome these barriers include building formal collaborations among researchers and clinicians, creating the infrastructure to support virtual recruitment and electronic consent, and developing contingency plans for studies involving the analysis of biological samples.

DISCUSSION

The neonatal intensive care unit is a unique environment because of vulnerable patient population and need for researchers to interact with parents to recruit study participants. Implementing the strategies developed during the coronavirus pandemic may allow for the continuation of research activities during future public health crises.

Neonatal Stress, Health, and Development in Preterms: A Systematic Review

CONTEXT

An overview of the full range of neonatal stressors and the associated clinical, laboratory, and imaging outcomes regarding infants' health and development may contribute to the improvement of neonatal care.

OBJECTIVE

To systematically review existing literature on the associations between all kinds of neonatal stressors and the health and development of preterm infants.

DATA SOURCES

Data sources included Embase, Medline, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature, and reference lists.

STUDY SELECTION

Studies were eligible if they included a measure of neonatal stress during the NICU stay, reported clinical, laboratory, and/or imaging outcomes regarding health and/or development on discharge from the NICU or thereafter, included preterm infants, and were written in English or Dutch.

DATA EXTRACTION

Two reviewers independently screened the sources and extracted data on health and development. Study quality was assessed by using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

We identified 20 articles that reported on neonatal stress associated negatively with clinical outcomes, including cognitive, motor, and emotional development, and laboratory and imaging outcomes, including epigenetic alterations, hypothalamic-pituitary-adrenal axis functioning, and structural brain development. We found no evidence regarding associations with growth, cardiovascular health, parent-infant interaction, the neonatal immune system, and the neonatal microbiome.

LIMITATIONS

The studies were all observational and used different definitions of neonatal stress.

CONCLUSIONS

Neonatal stress has a profound impact on the health and development of preterm infants, and physicians involved in their treatment and follow-up should be aware of this fact.

The impact of Nonpharmacological Interventions on Cortisol During Heel Lance Procedures on Preterm Infants: A Meta-Analysis Of RCTs

BACKGROUND

Current research suggests a need to implement environmental, behavioral, and even nutritional interventions, with the objective of improving the comfort and stability of preterm newborn infants, as well as reducing their stress and pain levels. Several studies have used the salivary reactivity of cortisol to assess stress or pain in preterm infants. The aim of this study was to analyze the results of published randomized controlled trials that tested the effects of nonpharmacological interventions on cortisol as a treatment for heel lance pain/stress in preterm infants.

METHODS

Published randomized controlled trials (RCTs) were searched in PubMed, Embase, CINHAL, Web of Science Cochrane Library, and Cochrane Database of Systematic Reviews, and six studies met the eligibility criteria. The quality of the included studies was appraised using Cochrane's Collaboration tool.

RESULTS

The meta-analysis showed that non-pharmacological interventions were associated with a reduction in levels of salivary cortisol in comparison with other interventions and controls, with fixed effect mean differences of -0.11, and with a 95% C.I. of -0.28 to -0.05. Prone-nest position, breast milk odor, kangaroo care, and twins co-bedding led to a decrease in cortisol levels in saliva.

CONCLUSION

Future studies should be performed on nonpainful interventions in order to gain more knowledge about the regulation of cortisol in saliva in preterm infants with involving control group and larger sample sizes.

A Behavioral Epigenetics Model to Predict Oral Feeding Skills in Preterm Infants

BACKGROUND

Preterm infants experience a multitude of prenatal and postnatal stressors, resulting in cumulative stress exposure, which may jeopardize the timely attainment of developmental milestones, such as achieving oral feeding. Up to 70% of preterm infants admitted to the neonatal intensive care unit experience challenges while initiating oral feeding. Oral feeding skills require intact neurobehavioral development. Evolving evidence demonstrates that cumulative stress exposure results in epigenetic modification of glucocorticoid-related genes. Epigenetics is a field of study that focuses on phenotypic changes that do not involve alterations in the DNA sequence. Epigenetic modification of glucocorticoid-related genes alters cortisol reactivity to environmental stimuli, which may influence neurobehavioral development, and is the essence of the evolving field of Preterm Behavioral Epigenetics. It is plausible that early-life cumulative stress exposure and the ensuing epigenetic modification of glucocorticoid-related genes impair neurobehavioral development required for achievement of oral feeding skills in preterm infants.

PURPOSE

The purpose of this article is to build upon the evolving science of Preterm Behavioral Epigenetics and present a conceptual model that explicates how cumulative stress exposure affects neurobehavioral development and achievement of oral feeding skills through epigenetic modification of glucocorticoid-related genes.

METHODS/RESULTS

Using the Preterm Behavioral Epigenetics framework and supporting literature, we present a conceptual model in which early-life cumulative stress exposure, reflected by DNA methylation of glucocorticoid-related genes and altered cortisol reactivity, disrupts neurobehavioral development critical for achievement of oral feeding skills.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Future investigations guided by the proposed conceptual model will benefit preterm infant outcomes by introducing epigenetic-based approaches to assess and monitor preterm infant oral feeding skills. Furthermore, the proposed model can guide future investigations that develop and test epigenetic protective interventions to improve clinical outcomes, representing an innovation in neonatal care.