NICU-based stress response and preterm infant neurobehavior: exploring the critical windows for exposure

Early Life Stress, DNA Methylation of NR3C1 and HSD11B2, and Oral Feeding Skill Development in Preterm Infants: A Pilot Study

BACKGROUND

Early life stress exposure in preterm infants may alter DNA methylation of NR3C1 and HSD11B2, disrupting neurobehaviors needed for oral feeding (PO) skill development.

PURPOSE

To (1) examine the feasibility of the study protocol; (2) describe early life stress, DNA methylation of NR3C1 and HSD11B2, and PO skill development; and (3) explore the association between DNA methylation of NR3C1 and HSD11B2 and infant characteristics, early life stress, and PO skill development.

METHOD

We employed a longitudinal descriptive pilot study (N = 10). Infant characteristics were collected from the infant's electronic medical record. Early life stress was assessed via the modified Neonatal Infant Stressor Scale. DNA methylation of NR3C1 exon 1F and HSD11B2 promoter regions was analyzed from the infant's buccal samples. PO skill development was evaluated using the Early Feeding Skills Assessment.

RESULTS

Infants who experienced more acute and chronic stress during their neonatal intensive care unit hospitalization demonstrated higher DNA methylation at CpG 17 and 31 of the NR3C1 exon 1F and at CpG 4 and 28 of the HSD11B2 promoter regions. Infants with higher DNA methylation at these CpG sites also exhibited less optimal PO skill development and experienced longer transition from first to full PO.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Our findings revealed relationships among early life stress, DNA methylation of NR3C1 and HSD11B2, and PO skill development in preterm infants. Future research is warranted to examine the multiomics pathways whereby early life stress influences the phenotypes of infant outcomes.

The effects of white noise and swaddling methods on orogastric tube insertion-related pain in preterm infants: A randomized controlled trial

AIM

This study aims to investigate the effects of the white noise, swaddling and white noise + swaddling methods on pain and physiological parameters associated with orogastric tube insertion procedure.

METHODS

This was a randomized controlled trial. A total of 132 preterm infants were randomly assigned to four groups as white noise group (n = 33), swaddling group (n = 33), white noise + swaddling group (n = 33) and control group (n = 33). Interventions were initiated 5 min before the orogastric tube insertion procedure and continued during and up to 5 min after the procedure.

RESULTS

White noise intervention alone did not have a significant effect on reducing pain associated with orogastric tube insertion (p > 0.05). Compared with the control group, the preterm infants in the swaddling group experienced 0.587 times less pain, and those in the white noise + swaddling group experienced 0.473 times less pain.

CONCLUSIONS

Findings indicate the swaddling and the combination of white noise + swaddling may be a useful intervention in reducing the invasive pain experienced by preterm infants during and after orogastric tube insertion and in improving the physiological parameters associated with pain.

Effects of mechanical ventilation on neurodevelopment at 12 months in preterm low birth weight pediatric patients: a systematic review

Introduction

The objective of this review is to know the existing scientific evidence about the effects of mechanical ventilation (MV) on neurological development in low-birth-weight premature pediatric patients after 12 months of life, taking as background the direct impact that ventilation has on the central nervous system in the newborn during the first days of life.

Methods

A systematic search was carried out between 2003 and 2024 in the data bases of: PUBMED, Cochrane Library Plus, PEDro, CINAHL, and SciELO, and two investigators scored the articles according to the Newcastle-Ottawa Assessment scale.

Results

Were found 129 non-replicated articles, and 10 cohort and cross-sectional studies were selected that performed an assessment of neurodevelopment in the three spheres after 12 months of life in corrected age of premature infants exposed to ventilator support and related the two variables independently.

Conclusions

Mechanical ventilation is an independent neurodevelopmental risk factor in low-birth-weight preterm infants. The time of exposure and the type of ventilation were the variables with the most scientific evidence.

Systematic Review Registration

https://www.crd.york.ac.uk/, Identifier CRD42023446797.

The effect of live-performed music therapy with physical contact in preterm infants on parental perceived stress and salivary cortisol levels

Introduction

Parents of preterm infants face a stressful life event which might have long term impact on the parent-child relation as well as on the infant's cognitive and socio-emotional development. Both music therapy (MT) and physical contact (PC) are stress-reducing interventions for parents and preterm infants on the neonatal intensive care unit (NICU). Meanwhile, especially close PC is considered as standard care (SC) in most NICUs. However, the effect of live performed MT with PC on parental perceived stress and cortisol levels has barely been investigated. We hypothesized that MT with PC leads to reduced stress levels and lower salivary cortisol concentrations compared to SC in parents of preterm infants during the first 4 weeks after birth.

Methods

Randomized-controlled trial enrolling the parents of 99 preterm infants (MT n = 50, SC n = 49 infants). The infants received either MT with PC or SC only. Perceived stress was measured with the perceived stress questionnaire 20 (PSQ-20) after birth and 4 weeks later. Salivary cortisol levels were obtained and measured weekly after birth for 4 weeks.

Results

Forty-two mothers and eight fathers of the intervention group (MT with PC) as well as n = 43 mothers and n = 6 fathers of the control group (SC) were enrolled. For the intervention group, salivary cortisol was reduced 4 weeks after birth [mothers 5.5 nmol/l (confidence interval (CI) 3.6-7.5); fathers 8.3 (CI 7.2-9.4)] compared to the control group [mothers 10.3 nmol/l (CI 5.4-15.3); fathers 14.8 (CI 8.9-20.7)]. Overall perceived stress scores decreased in the intervention group (mothers -17.6; fathers -12.6) and increased in the control group (mothers +6.1; fathers +21.4) over 4 weeks.

Discussion

Live-performed MT with PC in preterm infants might be an effective, non-invasive intervention to reduce parental stress and cortisol levels. Future studies should investigate the long-term effects of this intervention on the parent-infant relation as well as on the infants' cognitive and socio-emotional development.

Clinical trial registration

https://drks.de/search/en/trial/DRKS00025755 identifier [DRKS00025755].

Is an Exclusive Human Milk Diet at the Time of Neonatal Intensive Care Unit Discharge Adequate to Maintain Growth and Neurodevelopment among Very Preterm Infants?

Background: An exclusive human milk (EHM) diet has numerous benefits. Formula supplementation may be recommended for former preterm infants at the time of neonatal intensive care unit (NICU) discharge to meet perceived metabolic demands and caloric goals. Recommendations addressing postdischarge nutrition for very preterm infants (VPTIs) are controversial, as the benefits of human milk supplementation regarding long-term growth, neurodevelopment, and chronic conditions are mixed. Objective: To compare growth and neurodevelopment of former VPTI fed an EHM diet to a supplemented/formula diet at NICU discharge. Materials and Methods: A retrospective cohort study of VPTI was followed at the Regional Neonatal Follow-up Program. Patients were categorized by diet at NICU discharge: EHM diet; mixed diet (EHM and formula); and exclusive formula diet. Growth percentile ranks at the first neonatal follow-up visit and 3 years of age were compared by diet type at NICU discharge. Neurodevelopmental outcomes as measured by the Bayley Scales of Infant Development 3rd Edition at 3 years of age were also compared. Results: Among 835 VPTIs, weight percentiles at the first neonatal follow-up visit were similar between the three NICU discharge diet types. One hundred fifty-eight subjects received neurodevelopmental evaluations at 3 years of age; anthropometrics and neurodevelopment were similar irrespective of diet at NICU discharge. Conclusion: An EHM diet at NICU discharge is appropriate to support growth in infancy as well as growth and neurodevelopment through 3 years of age. Thus, this raises the question of whether routine nutritional supplementation is necessary for VPTIs at NICU discharge.

Neurobehavioral outcomes of preterm infants: toward a holistic approach

Children born very preterm (VPT; <32 weeks gestation) are at high risk for adverse developmental outcomes, yet not all children fare poorly. Some children born VPT have few or no neurodevelopmental concerns, while others have significant impairment in one or more domains. Historically, research has taken a variable-centered approach, reporting rates of impairment in single domains or single assessments as if they are independent of one another. More recently, child-centered approaches have been applied to studying outcomes for preterm children. Child-centered analyses allow us to integrate across multiple measures and domains to more holistically describe groups of children who vary in terms of the severity and co-occurrence of neurodevelopmental and behavioral strengths and difficulties. In this review, we will summarize current research that has taken a "whole child" approach to describing neurodevelopmental outcomes following preterm birth while highlighting the implications of this approach for research and clinical practice. We end by describing unanswered questions and areas that are in need of future research. IMPACT: Most research on outcomes for children born very preterm has reported rates of impairment in single domains or on single instruments. Recent findings suggest that a child-centered approach can identify unique phenotypes composed of multiple measures and domains that may be of clinical interest. A better understanding of unique combinations of neurodevelopmental and behavioral strengths and weaknesses could improve post-NICU care by emphasizing a personalized approach to intervention and treatment.

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.

Neurodevelopmental outcome of low-risk moderate to late preterm infants at 18 months

Background

Of the 15 million preterm births that occur worldwide each year, approximately 80% occur between 32 and 36 + 6 weeks gestational age (GA) and are defined as moderate to late preterm (MLP) infants. This percentage substantiates a need for a better understanding of the neurodevelopmental outcome of this group.

Aim

To describe neurodevelopmental outcome at 18 months in a cohort of healthy low-risk MLP infants admitted to the neonatal unit at birth and to compare the neurodevelopmental outcome to that of a healthy term-born infant group.

Study design and method

This single-centre observational study compared the neurodevelopmental outcome of healthy MLP infants to a group of healthy term control (TC) infants recruited during the same period using the Griffith's III assessment at 18 months.

Results

Seventy-five MLP infants and 92 TC infants were included. MLP infants scored significantly lower in the subscales: Eye-hand coordination (C), Personal, Social and Emotional Development (D), Gross Motor Development (E) and General Developmental (GD) (p < 0.001 for each) and Foundations of Learning (A), (p = 0.004) in comparison to the TC infant group with Cohen's d effect sizes ranging from 0.460 to 0.665. There was no statistically significant difference in mean scores achieved in subscale B: Language and Communication between groups (p = 0.107).

Conclusion

MLP infants are at risk of suboptimal neurodevelopmental outcomes. Greater surveillance of the neurodevelopmental trajectory of this group of at-risk preterm infants is required.

Prenatal and perinatal factors associated with neonatal neurobehavioral profiles in the ECHO Program

BACKGROUND

Single-cohort studies have identified distinct neurobehavioral profiles that are associated with prenatal and neonatal factors based on the NICU Network Neurobehavioral Scale (NNNS). We examined socioeconomic, medical, and substance use variables as predictors of NNNS profiles in a multi-cohort study of preterm and term-born infants with different perinatal exposures.

METHODS

We studied 1112 infants with a neonatal NNNS exam from the Environmental influences on Child Health Outcomes (ECHO) consortium. We used latent profile analysis to characterize infant neurobehavioral profiles and generalized estimating equations to determine predictors of NNNS profiles.

RESULTS

Six distinct neonatal neurobehavioral profiles were identified, including two dysregulated profiles: a hypo-aroused profile (16%) characterized by lethargy, hypotonicity, and nonoptimal reflexes; and a hyper-aroused profile (6%) characterized by high arousal, excitability, and stress, with low regulation and poor movement quality. Infants in the hypo-aroused profile were more likely to be male, have younger mothers, and have mothers who were depressed prenatally. Infants in the hyper-aroused profile were more likely to be Hispanic/Latino and have mothers who were depressed or used tobacco prenatally.

CONCLUSIONS

We identified two dysregulated neurobehavioral profiles with distinct perinatal antecedents. Further understanding of their etiology could inform targeted interventions to promote positive developmental outcomes.

IMPACT

Prior research on predictors of neonatal neurobehavior have included single-cohort studies, which limits generalizability of findings. In a multi-cohort study of preterm and term-born infants, we found six distinct neonatal neurobehavioral profiles, with two profiles being identified as dysregulated. Hypo- and hyper-aroused neurobehavioral profiles had distinct perinatal antecedents. Understanding perinatal factors associated with dysregulated neurobehavior could help promote positive developmental outcomes.

The relationship between NICU stress and neurodevelopmental outcomes of preterm infants: A multi-center prospective cohort study in China

PURPOSE

To examine the relationship between NICU stress exposure and the neurodevelopmental outcomes of preterm infants.

DESIGN AND METHODS

A multicenter, prospective cohort study was conducted between May 2021 and June 2022. Preterm infant participants (28-34 weeks gestational age) were recruited at birth from three NICUs of three tertiary hospitals by convenience sampling. The NICU stress includes acute NICU stress and chronic NICU stress which were measured over the total NICU hospitalization for each infant using the Neonatal Infant Stressor Scale (NISS). Neurodevelopmental outcomes of preterm infants were assessed at 3 months corrected age (CA) using the Ages and Stages Questionnaire, Third Edition (ASQ-3).

RESULTS

Of one hundred and thirty preterm infant participants, 108 preterm infants were included into analysis. Results showed that acute NICU stress exposure significantly predicted the neurodevelopmental abnormalities in communication function (RR: 1.001, 95%CI: 1.000-1.001, p = .011), while chronic NICU stress exposure was significantly associated with the problem-solving function (RR: 1.003, 95%CI: 1.001-1.005, p = .002) at 3 months CA. No significant associations were found between NICU stress exposure and other dimensions of neurodevelopmental outcomes, including gross motor, fine motor, and personal-social functions.

CONCLUSION

NICU stress exposure demonstrated a significant predicting relationship with abnormalities in communication and problem-solving functions of preterm infants at 3 months CA.

PRACTICE IMPLICATIONS

During the NICU hospitalization, neonatal health caregivers should systematically monitor the NICU stress exposure to prevent neurodevelopmental problems in preterm infants.