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

The relationship between neonatal stress in preterm infants and developmental outcomes at the corrected age of 24-30 months

Aim

The aim of research was to study the relationship between the stress experienced by preterm infants in the neonatal intensive care unit (NICU) and developmental status in the follow up, and to establish factors, associated with their neurodevelopment.

Methods

The first stage of research involved measuring stress markers (cortisol, melatonin) in infants (n = 56) during their NICU stay; the second phase assessed the developmental status at the corrected age of 24-30 months.

Results

The total ASQ-3 score, communication, problem solving, and personal-social skills scores at the corrected age of 24-30 months were positively correlated with melatonin level determined in the neonatal period (r = 0.31, p = 0.026; r = 0.36, p = 0.009; r = 0.30, p = 0.033, and r = 0.32; p = 0.022 respectively). In the same time, ASQ-3 communication and personal-social scores were negatively correlated with cortisol level (r = -0.31, p = 0.043; r = -0.35, p = 0.022). The ROC-curve analysis revealed that a decrease of melatonin below 3.44 ng/mL and 3.71 ng/mL during the neonatal period could predict communication and problem-solving delay, respectively. An increase in cortisol above 0.64 mcg/dl is predictive in personal-social delay. Negative correlation was identified between the NICU and total hospital stay duration and ASQ-3 communication scores in the follow-up (r = -0.27; p = 0.049 and r = -0.41; p = 0.002, respectively). The duration of mechanical ventilation was negatively correlated with gross motor scores (r = -0.46; p = 0.043). Apgar score was positively correlated with ASQ-3 communication (r = 0.29; p = 0.032) and personal-social scores (r = 0.28; p = 0.034); maternal age-with ASQ-3 total (r = 0.29; p = 0.034), communication (r = 0.37; p = 0.006), and personal-social scores (r = 0.29; p = 0.041). Positive correlations were observed between gestational age and communication scores (r = 0.28; p = 0.033). Infants who suffered neonatal sepsis had significantly often delay of communication (p = 0.014) and gross motor skills (p = 0.016). Children who required mechanical ventilation were more likely to have communication delay (p = 0.034).

Conclusion

Developmental outcomes in preterm infants at the corrected age of 24-30 months were associated with neonatal stress. Correlations between the communication, problem-solving and personal-social development in the follow up and cortisol and melatonin levels determined in the neonatal period supported this evidence. Factors as low gestational age, duration of hospital and NICU stay, mechanical ventilation, and sepsis were associated with more frequent delays in communication, gross motor and problems-solving skills.

Comparing conventional and modified Seldinger techniques using a micro-insertion kit for PICC placement in neonates: a retrospective cohort study

Objective

This study aims to assess the comparative effectiveness of a conventional splitting needle or a peelable cannula vs. the modified Seldinger technique (MST) by utilizing a dedicated micro-insertion kit across various clinically significant metrics, including insertion success, complications, and catheter-related infections.

Methods

We conducted a retrospective observational cohort study using an anonymized data set spanning 3 years (2017-2019) in a large tertiary-level neonatal intensive care unit in Qatar.

Results

A total of 1,445 peripherally inserted central catheter (PICC) insertion procedures were included in the analysis, of which 1,285 (89%) were successful. The primary indication for insertion was mainly determined by the planned therapy duration, with the saphenous vein being the most frequently selected blood vessel. The patients exposed to MST were generally younger (7 ± 15 days vs. 11 ± 26 days), but exhibited similar mean weights and gestational ages. Although not statistically significant, the MST demonstrated slightly higher overall and first-attempt insertion success rates compared to conventional methods (91 vs. 88%). However, patients undergoing conventional insertion techniques experienced a greater incidence of catheter-related complications (p < 0.001). There were 39 cases of catheter-related bloodstream infections (CLABSI) in the conventional group (3.45/1,000 catheter days) and eight cases in the MST group (1.06/1,000 catheter days), indicating a statistically significant difference (p < 0.001). Throughout the study period, there was a noticeable shift toward the utilization of the MST kit for PICC insertions.

Conclusion

The study underscores the viability of MST facilitated by an all-in-one micro kit for neonatal PICC insertion. Utilized by adept and trained inserters, this approach is associated with improved first-attempt success rates, decreased catheter-related complications, and fewer incidences of CLABSI. However, while these findings are promising, it is imperative to recognize potential confounding factors. Therefore, additional prospective multicenter studies are recommended to substantiate these results and ascertain the comprehensive benefits of employing the all-in-one kit.

Early stress during NICU stay and parent-reported health-related quality of life after extremely preterm birth: an exploratory study with possible targets for early intervention

Introduction

The association between neonatal intensive care unit (NICU) related stress in preterm infants and their health-related quality of life (HRQoL) in the first year following preterm birth remains unexplored. Understanding this association is crucial for enhancing preventive and supportive measures for infants and parents within and beyond the NICU.

Methods

From a single center observational cohort study, we included infants with gestational ages below 30 weeks and/or birth weights under 1,000 grams. HRQoL was quantified using the Infant Quality of Life Instrument (IQI) at 3-, 6-, 9- and 12-months corrected age, covering seven domains. NICU stress was quantified using the Neonatal Infant Stressor Scale (NISS) for the first week of life. We performed Spearman's correlation analyses to test this association.

Results

Of the 45 included infants, the IQI was completed for 27 (60%) at 3, 15 (33%) at 6, 14 (31%) at 9 and 15 (33%) at 12 months. The HRQoL sum scores were related to neonatal stress at 9 and 12 months (ρ = 0.643 and 0.591, p = 0.013 and p = 0.019, respectively) but not at 3 and 6 months (ρ = -0.001 and -0.077 respectively, p > 0.05). Higher NICU stress tended to be associated with more respiratory and mood problems throughout the first year.

Discussion

From a parental perspective on infant HRQoL, extremely preterm infants with higher stress exposure show more problems in the second half-year of life, mainly breathing and possibly mood-related problems. This knowledge may help improve our neonatal care, both during NICU stay and in follow-up clinics, by implementing targeted interventions.

Application of the Adverse Childhood Experiences Framework to the NICU

BACKGROUND

Infants and families requiring neonatal intensive care unit (NICU) care often experience significant stress and trauma during the earliest period of the infant's life, leading to increased risks for poorer infant and family outcomes. There is a need for frameworks to guide clinical care and research that account for the complex interactions of generational stress, pain, toxic stress, parental separation, and lifelong health and developmental outcomes for infants and families.

PURPOSE

Apply the Adverse Childhood Experiences (ACEs) framework in the context of the NICU as a usable structure to guide clinical practice and research focused on infant neurodevelopment outcomes and parental attachment.

METHODS

An overview of ACEs is provided along with a detailed discussion of risk at each level of the ACEs pyramid in the context of the NICU. Supportive and protective factors to help mitigate the risk of the ACEs in the NICU are detailed.

RESULTS

NICU hospitalization may be considered the first ACE, or potentially an additional ACE, resulting in an increased risk for poorer health outcomes. The promotion of safe, stable, and nurturing relationships and implementation of trauma-informed care and individualized developmental care potentially counter the negative impacts of stress in the NICU.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Nurses can help balance the negative and positive stimulation of the NICU through activities such as facilitated tucking, skin-to-skin care, mother's milk, and active participation of parents in infant care. Future research can consider using the ACEs framework to explain cumulative risk for adverse health and well-being in the context of NICU care.

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.

Neonatal stress exposure and DNA methylation of stress-related and neurodevelopmentally relevant genes: An exploratory study

BACKGROUND

Stress exposure during Neonatal Intensive Care Unit (NICU) stay may have long-lasting effects on neurodevelopmental outcomes in extremely preterm infants. Altered DNA methylation of stress-related and neurodevelopmentally relevant genes may be an underlying mechanism.

AIMS

This exploratory study aimed to investigate the association between neonatal stress exposure and DNA methylation in these genes at two different time points: early during the NICU stay (7-14 days after birth) and later, at discharge from the NICU.

SUBJECTS

We included 45 extremely preterm infants in this prospective cohort study, gestational age 24-30 weeks.

OUTCOME MEASURES

We collected fecal samples at days 7-14 (n = 44) and discharge (n = 28) and determined DNA methylation status in predefined regions of NR3C1, SLC6A4, HSD11B2, OPRM1, SLC7A5, SLC1A2, IGF2, NNAT, BDNF and GABRA6 using pyrosequencing. Because of low DNA concentrations in some fecal samples, we could do so in 25-50 % of collected samples. We prospectively quantified daily neonatal stress exposure using the Neonatal Infant Stressor Scale (NISS) and explored associations between cumulative NISS scores and average DNA methylation status.

RESULTS

Rates of methylation of most genes were not statistically different between day 7-14 and discharge, except for OPRM1. We found moderately high and mostly negative correlation coefficients upon discharge with the cumulative NISS for the NR3C1, SLC6A4, SLC1A2, IGF2, BDNF and OPRM1 genes, albeit not statistically significant.

CONCLUSIONS

Findings suggest that expression of stress-related and neurodevelopmentally relevant genes may be differently regulated following higher neonatal stress exposure. Larger studies should challenge the findings of this study and ideally test the effects on gene expression.

The Optimal State Scoring Tool: guidance for interdisciplinary care of infants with severe bronchopulmonary dysplasia and its relation to linear growth

OBJECTIVE

Infants with severe bronchopulmonary dysplasia (sBPD) have complex medical courses. We developed the clinician-rated Optimal State Scoring Tool (OSST) that measures factors relevant to clinical improvement of sBPD and investigated preliminary validity using linear growth outcome and OSST scores in sBPD patients.

METHODS

Tool development process and pilot findings are provided for 13 patients evaluated longitudinally. OSST scores, length measurements, and steroid dependency values were obtained. Changes in OSST scores and lengths were examined using linear mixed-effect models.

RESULTS

OSST scores were significantly correlated with linear growth (95% CI 0.36, 0.57). The steroid-dependent group showed significantly slower rate of linear growth (95% CI 0.74, 1.05) and slower rate of increase in OSST scores (95% CI 0.99, 2.13) compared to the non-steroid-dependent group, with the OSST showing the largest effect size.

CONCLUSION

Pilot data reflect promising evidence for OSST construct validity in monitoring clinical outcomes in sBPD patients.

Scoping Review of Early Toxic Stress and Epigenetic Alterations in the Neonatal Intensive Care Unit

BACKGROUND

Preterm infants are uniquely vulnerable to early toxic stress exposure while in the neonatal intensive care unit (NICU) and also being at risk for suboptimal neurodevelopmental outcomes. However, the complex biological mechanisms responsible for variations in preterm infants' neurodevelopmental outcomes because of early toxic stress exposure in the NICU remain unknown. Innovative preterm behavioral epigenetics research offers a possible mechanism and describes how early toxic stress exposure may lead to epigenetic alterations, potentially affecting short- and long-term outcomes.

OBJECTIVE

The aim of this study was to review the relationships between early toxic stress exposures in the NICU and epigenetic alterations in preterm infants. The measurement of early toxic stress exposure in the NICU and effect of epigenetic alterations on neurodevelopmental outcomes in preterm infants were also examined.

METHODS

We conducted a scoping review of the literature published between January 2011 and December 2021 using databases PubMed, CINAHL, Cochrance Library, PsycINFO, and Web of Science. Primary data-based research that examined epigenetics, stress, and preterm infants or NICU were included.

RESULTS

A total of 13 articles from nine studies were included. DNA methylations of six specific genes were studied in relation to early toxic stress exposure in the NICU: SLC6A4, SLC6A3, OPRMI, NR3C1, HSD11B2, and PLAGL1. These genes are responsible for regulating serotonin, dopamine, and cortisol. Poorer neurodevelopmental outcomes were associated with alterations in DNA methylation of SLC6A4, NR3C1, and HSD11B2. Measurements of early toxic stress exposure in the NICU were inconsistent among the studies.

DISCUSSION

Epigenetic alterations secondary to early toxic stress exposures in the NICU may be associated with future neurodevelopmental outcomes in preterm infants. Common data elements of toxic stress exposure in preterm infants are needed. Identification of the epigenome and mechanisms by which early toxic stress exposure leads to epigenetic alterations in this vulnerable population will provide evidence to design and test individualized intervention.

Touch Experiences of Preterm Infants During Essential Nursing Care

Purpose: To characterize and quantify touch experienced by preterm infants in the NICU during essential nursing care, identify instances of skin-to-skin touch between infants and caregivers, and identify clinical/demographic variables associated with touch experiences. Design: Cross-sectional study. Sample: Preterm infants (N = 20) born 27-32 weeks post-menstrual age. Main Outcome Variable: Categories of touch during observations. Results: Touch experienced by infants during day and night shifts was primarily direct touch that was further categorized as general handling. During day shifts, 30 percent of direct touch was provided for comfort, but only 9.7 percent of touch was provided exclusively for comfort (i.e., without more intrusive touch). During night shifts, 10.6 percent of direct touch was provided for comfort, and 3 percent was categorized as exclusive comforting touch. Caregivers wore gloves for >89 percent of infant touch. Only the level of respiratory support was associated with touch categories during both shifts.

Quantification of stress exposure in very preterm infants: Development of the NeO-stress score

BACKGROUND

Stress during treatment at the Neonatal Intensive Care Unit (NICU) has long-term negative consequences on preterm infants' development.

AIMS

We developed an instrument suited to validly determine the cumulative stress exposure for preterm infants in a NICU.

STUDY DESIGN

This survey study made use of two consecutive questionnaires.

SUBJECTS

NICU nurses and physicians from the nine NICUs in the Netherlands.

OUTCOME MEASURES

First, respondents rated the relevance of 77 items encompassing potentially stressful procedures, commented on their comprehensibility and the comprehensiveness of the list. We calculated the content validity per item (CVI-I) and included only the relevant items in a second questionnaire in which the participants rated the stressfulness from 0 (not stressful) to 10 (extremely stressful). A stressfulness index - representing the median score - was calculated for each included item.

RESULTS

Based on the CVI-I of the 77 items, step 1 resulted in 38 items considered relevant to quantify stress in preterm infants during the first 28 days of life. This list of 38 items exists of 34 items with a CVI-I if 0.78 or higher, one of these items was split into two items, and three items were added to improve comprehensiveness. The stressfulness index ranged from five to nine.

CONCLUSIONS

The NeO-stress score consists of stressful items including their severity index and was developed to determine cumulative stress exposure of preterm infants. Evaluating the cross-cultural validity, correlating it to behavioural and biological stress responses, and evaluating its ability to predict preterm infants at risk for the negative effects following stress might expand the possibilities for this instrument.

An integrative review of clinician-administered comforting touch interventions and acute stress responses of preterm infants

PROBLEM

Preterm infants experience numerous stressors in the neonatal intensive care unit. Non-pharmacological interventions, including maternal comforting touch, reduce stress responses of preterm infants; however, the effects of clinician-administered comforting touch are unclear. The purpose of this integrative review was to synthesize findings from clinical trials to determine the effect of clinician-administered comforting touch on preterm infants' acute stress responses.

ELIGIBILITY CRITERIA

Eligible clinical trials were published in English between 2001 and October 2021 and reported effects of clinician-administered comforting touch on acute stress responses in preterm infants.

SAMPLE

Thirty clinical trials were included.

RESULTS

Researchers tested the effect of comforting static touch, massage, massage with kinesthetic stimulation, sensorial saturation, and Yakson. There was significant heterogeneity in study design, comparison condition, and context of intervention delivery. Results varied; some studies demonstrated efficacy of comforting touch in reducing acute stress responses and others showed no effect. Generally, comforting touch provided during stressful procedures was associated with lower stress responses compared to standard care and was an effective adjunct to other stress management strategies. However, comforting touch alone was insufficient for managing pain, especially during skin-breaking procedures.

CONCLUSIONS

While comforting touch may be a useful part of stress management plans for preterm infants, additional research is needed to determine when comforting touch is appropriate and effective.

IMPLICATIONS

Comforting touch is beneficial to preterm infants and should be provided for stress management. For highly intrusive or painful procedures, comforting touch can be provided as part of a comprehensive stress management plan.

Neurobehavior in very preterm infants with low medical risk and full-term infants

OBJECTIVE

To describe differences in neurobehavior among very preterm infants with low medical risk at term equivalent age and full-term infants.

STUDY DESIGN

One-hundred eighty-six (136 infants born ≤32 weeks gestation with low medical risk at term equivalent age and 50 full-term infants within 4 days of birth) had standardized neurobehavioral assessments. Low medical risk was defined by ventilation <10 days and absence of significant brain injury, necrotizing enterocolitis, patent ductus arteriosus, and retinopathy of prematurity.

RESULTS

Very preterm infants with low medical risk at term equivalent age demonstrated more sub-optimal reflexes (p < 0.001; ß = 1.53) and more stress (p < 0.001; ß = 0.08) on the NICU Network Neurobehavioral Scale compared to their full-term counterparts. Very preterm infants with low medical risk also performed worse on the Hammersmith Neonatal Neurological Examination (p = 0.005; ß = -3.4).

CONCLUSION

Very preterm infants at term equivalent age continue to demonstrate less optimal neurobehavior compared to full-term infants.

Ten Years of Neonatal Intensive Care Adaption to the Infants' Needs: Implementation of a Family-Centered Care Model with Single-Family Rooms in Norway

Ten years ago, the Neonatal intensive care unit in Drammen, Norway, implemented Single-Family Rooms (SFR), replacing the traditional open bay (OB) unit. Welcoming parents to stay together with their infant 24 h per day, seven days per week, was both challenging and inspiring. The aim of this paper is to describe the implementation of SFR and how they have contributed to a cultural change among the interprofessional staff. Parents want to participate in infant care, but to do so, they need information and supervision from nurses, as well as emotional support. Although SFR protect infants and provide private accommodation for parents, nurses may feel isolated and lack peer support. Our paper describes how we managed to systematically reorganize the nurse's workflow by using a Plan-Do-Study-Act (PDSA) cycle approach. Significant milestones are identified, and the implementation processes are displayed. The continuous parental presence has changed the way we perceive the family as a care recipient and how we involve the parents in daily care. We provide visions for the future with further developments of care adapted to infants' needs by providing neonatal intensive care with parents as equal partners.

Differential Placental DNA Methylation of NR3C1 in Extremely Preterm Infants With Poorer Neurological Functioning

BACKGROUND

Understanding underlying mechanisms of neurodevelopmental impairment following preterm birth may enhance opportunities for targeted interventions. We aimed to assess whether placental DNA methylation of selected genes affected early neurological functioning in preterm infants.

METHODS

We included 43 infants, with gestational age <30 weeks and/or birth weight <1,000 g and placental samples at birth. We selected genes based on their associations with several prenatal conditions that may be related to poor neurodevelopmental outcomes. We determined DNA methylation using pyrosequencing, and neurological functioning at 3 months post-term using Prechtl's General Movement Assessment, including the Motor Optimality Score-Revised (MOS-R).

RESULTS

Twenty-four infants had atypical MOS-R, 19 infants had near-optimal MOS-R. We identified differences in average methylation of NR3C1 (encoding for the glucocorticoid receptor) [3.3% (95%-CI: 2.4%-3.9%) for near-optimal vs. 2.3% (95%-CI: 1.7%-3.0%), p = 0.008 for atypical], and at three of the five individual CpG-sites. For EPO, SLC6A3, TLR4, VEGFA, LEP and HSD11B2 we found no differences between the groups.

CONCLUSION

Hypomethylation of NR3C1 in placental tissue is associated with poorer neurological functioning at 3 months post-term in extremely preterm infants. Alleviating stress during pregnancy and its impact on preterm infants and their neurodevelopmental outcomes should be further investigated.