Effects of the neonatal intensive care environment on circadian health and development of preterm infants

The Effect of a Chronobiological Feeding Model on Growth Parameters and Length of Hospitalization in Preterm Infants: A Randomized Controlled Study

Background and Purpose: Preterm infants are born before the 37th gestational week and need prompt nutrition. The circadian rhythm is an internal 24-hour cycle regulated by endogenous molecules. Human milk contains different biological peptides at different times within this cycle. Chrononutrition is a feeding model that is adjusted to match the biological clock of the individual. This study tests chrononutrition as a superior feeding model in preterm infants. This study aimed to evaluate the effect of the chronobiological feeding model on growth parameters and discharge time among preterm infants. Methods: We conducted a prospective, randomized controlled trial in a tertiary neonatal intensive care unit between October 2021 and March 2022, randomized preterm infants to receive either chrononutrition (study group = 45) or standard feeding (control group = 46), and used the infant's follow-up form for data collection. Results: Among 91 neonates, the median gestational age was 33 weeks, and the mean birth weight was 2,100 g. Demographic findings and growth parameters showed no difference between the groups (p > 0.05). Weight gain and percentile measurements at discharge were statistically significantly higher in the study group (p = 0.002 and p = 0.003, respectively). Discharge time was statistically significantly lower after full enteral feeding and hospitalization time was shorter in the study group (p = 0.001). Conclusions: The chronobiological feeding model showcased significant positive effects on anthropometrics and percentile measurements at discharge and led to a 2-day reduction in the length of hospital stay.

Circadian Rhythms, Immune Regulation, and the Risk for Sepsis: Circadian Rhythms and Neonatal Care

Circadian rhythms provide an anticipatory mechanism for organisms to adapt to environmental changes. Host response to infections is under robust circadian control. Most of the existing literature focuses on adults in epidemiologic and animal studies. Neonatal and early infancy represent critical windows in the consolidation of circadian rhythms. This review summarizes our understanding of the molecular clock, especially its relevance to immunity and adult sepsis. Further, using our knowledge of circadian biology in caring for a newborn host with emerging circadian rhythms represents a unique challenge and an opportunity for improving our approach and outcomes in neonatal sepsis.

Individualized developmental care interventions for promoting development and preventing morbidity in preterm infants

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the benefits and harms of individualized developmental care interventions for promoting development and preventing morbidity in preterm infants.

The development of preterm infants from low socio-economic status families: The combined effects of melatonin, autonomic nervous system maturation and psychosocial factors (ProMote): A study protocol

Preterm births constitute a major public health issue and a chronic, cross-generational condition globally. Psychological and biological factors interact in a way that women from low socio-economic status (SES) are disproportionally affected by preterm delivery and at increased risk for the development of perinatal mental health problems. Low SES constitutes one of the most evident contributors to poor neurodevelopment of preterm infants. Maternal perinatal mental health disorders have persistent effects on behavioral and physiological functioning throughout the lifespan and may even be evident across generations. The overall objective of the proposed longitudinal, multi-disciplinary and multi-method study is to compare the association of psychosocial (maternal mental health, intersubjectivity, attachment, family functioning, dyadic coping and perceived social support), and biological factors (melatonin and heart rate variability) with preterm infants' development at 9 months (corrected age), between low and high SES families. We will collect data from preterm neonates (<37 weeks gestational age) hospitalized in the Department of Neonatology/Neonatal Intensive Care Unit of the University General Hospital of Heraklion, Greece, and their mothers. Data collection of psychosocial and biological factors will be carried out at birth, and at the corrected age of 6 and 9 months, while preterm infants' cognitive and social development will be assessed at 9 months corrected age. The findings of this study may highlight the need for early interventions for new mothers coming from low SES in order to promote their preterm infants' optimal early neurodevelopment and for community-evidence-based prevention efforts to restrict the cycle of health inequities and intergenerational mental disorders.

Cycled light in the intensive care unit for preterm and low birth weight infants

BACKGROUND

Preterm and low birth weight infants are at an early stage of development, and do not receive adequate maternal circadian signals. They are often cared for over prolonged periods of hospitalisation in neonatal intensive care units (NICU), where environmental circadian stimuli are lacking. Exposure to artificial light-dark cycles may stimulate the development of the circadian system and improve clinical outcomes. However, it remains uncertain whether cycled light (CL) is preferable to near darkness (ND) or continuous bright light (CBL) in fostering development and maturation, and reducing adverse neonatal health outcomes. This is an update of an earlier Cochrane review, last published in 2016.

OBJECTIVES

To evaluate the benefits and harms of CL in preterm and low birth weight infants compared to ND or CBL.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, and two trial registries to September 2023. We also checked reference lists, and searched for retractions of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs in preterm infants (< 37 weeks' postmenstrual age (PMA)), or those with a low birth weight (< 2500 g), admitted and cared for in an NICU or a step-down unit, comparing CL with ND or CBL.

DATA COLLECTION AND ANALYSIS

We used the standard review methods of the Cochrane Neonatal Review Group to assess the methodological quality of studies. We used the fixed-effect model with risk ratio (RR) and mean difference (MD), with their 95% confidence intervals (CIs) for dichotomous data. Our primary outcomes were (1) growth at three and six months' corrected age, (2) major neurodevelopmental disability, and (3) adverse effects. Our secondary outcomes were (4) retinopathy of prematurity, (5) duration of initial hospitalisation, (6) duration of oxygen treatment, and (7) parent satisfaction. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 20 studies with 1633 infants. Data for meta-analysis were available for 11 studies (1126 infants). One study with multiple arms was included in both comparisons. We rated the overall risk of bias at the study level as high or unclear for all 20 studies that had one or several unclear or high risk of bias judgements across the domains. Cycled light versus dimmed light or near darkness (10 studies) The evidence is very uncertain about the effect of cycled light compared to dimmed light (reduction of illumination levels) or near darkness on weight at three months (MD 24.79, 95% CI -262.33 to 311.91; 2 studies, 187 infants; very low-certainty evidence), and weight at six months (MD 202, 95% CI -109.68 to 513.68; 1 study, 147 infants; very low-certainty evidence). The studies did not report any data for major neurodevelopmental disability. No data are available for adverse effects; it is uncertain if the absence of adverse effects is because none occurred, or because they were not identified and recorded. The evidence is very uncertain about the effect of cycled light compared to dimmed light or near darkness on the likelihood of developing retinopathy of prematurity of any stage (RR 0.89, 95% CI 0.76 to 1.03; 3 studies, 307 infants; very low-certainty evidence), and severe retinopathy of prematurity of stage 3 or higher (RR 0.98, 95% CI 0.59 to 1.61; 4 studies, 454 infants; very low-certainty evidence). Cycled light compared to dimmed light or near darkness may have little to no effect on the duration of initial hospitalisation (MD -3.04, 95% CI -7.86 to 1.78; 5 studies, 550 infants; very low-certainty evidence), but the evidence is very uncertain. Cycled light versus continuous bright light (11 studies) No data are available on the following primary outcomes, as no studies reported them: growth at three and six months' corrected age, major neurodevelopmental disability, and adverse effects. It is uncertain if the absence of adverse effects is because none occurred or because they were not identified and recorded. No data are available on retinopathy of prematurity, as no studies reported it. Cycled light compared to continuous bright light may reduce the duration of initial hospitalisation, but the evidence is very uncertain (MD -9.86, 95% CI -10.09 to -9.63; 5 studies, 499 infants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Despite identifying 20 studies, we remain uncertain about the effect of CL compared to ND or CBL on all outcomes of interest in this review. In addition, a few critical outcomes were not reported by any of the included studies. The evidence remains uncertain about whether CL is the right choice in the NICU. The physician should always weigh the benefits and risks, based on the effects of the different options in the specific setting.

Multi-omics insights into beagle dog fed with a sucking-rewarded automatic feeding device

Background

Facilitating the development of the sucking function in early stages of preterm infants holds substantial potential for influencing their long-term outcomes. To this end, our team has devised a sucking-rewarded automatic feeding device specifically tailored for preterm infants. The present study is designed to investigate the impacts of this innovative device, utilizing a multi-omics profiling approach, on beagle dogs as a surrogate model.

Methods

This study involved seven-day-old male newborn beagle puppies, carefully selected and matched in terms of body weights. The participants were stratified into two groups: the experimental group (AFG, sucking-rewarded feeding group) and the control group (PFG). After a 14-day intervention period, fecal and blood samples were systematically collected from each dog. The collected samples were then subjected to distinct profiling analyses, encompassing the assessment of gut microbial composition, plasma metabolic profiles, and proteomic expression profiles.

Results

The gut microbial data showed a significant difference between the AFG and PFG groups based on Bray-Curtis dissimilarity (P = 0.048), and the relative abundance of Lactobacillus was significantly more abundant in the AFG group compared to the PFG group. The significantly different metabolites between the two groups were enriched in functional metabolic pathways related to amino acids, fatty acid metabolism, and the nervous system. Notably, neurotransmitter L-glutamic acid was significantly up-regulated in the AFG group. Moreover, the significantly different proteins between the two groups were enriched in GO terms related to oxygen transport, oxygen binding, iron ion binding, hemoglobin complex, and heme binding. Among them, proteins A0A8C0MTD2, P60524, P60529 were significantly up-regulated in the AFG group. Notably, Lactobacillus, L-glutamic acid, A0A8C0MTD2, P60524, and P60529 were correlated with each other through correlation analysis, these molecules play important roles in the neural function and neurodevelopment.

Conclusion

Our investigation elucidated discernible modifications in gut microbial composition, plasma metabolic profiles, and proteomic expression patterns in beagle dogs subjected to the sucking-rewarded automatic feeding device.

The impact of skin-to-skin contact upon stress in preterm infants in a neonatal intensive care unit

Introduction

Neonatal stress significantly affects the early adaptation, maturation and long-term development of preterm infants.

The objective of the study

To investigate the effect of skin-to-skin contact (SSC) on stress level in preterm infants.

Materials and methods

The research was a prospective study. Stress indicators (cortisol, melatonin) were measured before the SSC began (pre-intervention level) and after this intervention (post-intervention).

Results

The study included 150 preterm infants in the NICU with gestational age (GA) ≤36 weeks. Pre-intervention salivary cortisol level was higher in extremely and very preterm neonates compared to moderate and late preterm newborns (p = 0.028), in children with low Apgar scores (p = 0.041), in those who were on mechanical ventilation (p = 0.005), and suffered neonatal sepsis (p = 0.005). Pre-intervention melatonin level was lower in children with low Apgar scores (p = 0.032). Salivary cortisol levels were significantly decreased after SSC in preterm infants [pre-intervention: 0.294 (0.111; 0.854) μg/dL vs. post-intervention: 0.127 (0.070; 0.229) μg/dL, p < 0.001], and urinary melatonin levels were significantly increased after SSC [pre-intervention: 4.01 (2.48; 6.34) ng/mL vs. post-intervention: 5.48 (3.39; 9.17) ng/mL, p < 0.001]. A greater reduction in cortisol levels after skin-to-skin contact was revealed in infants with a lower gestational age (p = 0.022), in boys compared to girls (p = 0.012), in infants with respiratory distress syndrome (p = 0.048), in those who had mechanical ventilation compared to non-ventilated neonates (p = 0.008), and in infants with seizures (p = 0.036). The melatonin levels increased more intensively in infants with low Apgar scores (p = 0.002), and in those with late-onset sepsis (p = 0.006).

Conclusion

The reduction in cortisol levels and the increase in melatonin levels provided strong evidence that SSC ameliorated the NICU-related stress in preterm infants. We found higher indicators of stress and more dramatic responses to SSC in reducing indicators of stress in infants with lower GA than in infants with higher GA, indicating that SSC may be even more important for lower GA infants. The infants who need SSC the most should not be denied the care they need to reduce the stress they experience from being born too soon and continuing their gestational development in the stressful environment of the NICU.

The Effect of a Light-Dark Cycle on Premature Infants in the Neonatal Intensive Care Unit: A Randomized Controlled Study

PURPOSE

To investigate potential differences in discharge time, feeding methods and amounts, daily weight gain, vital signs, pain, and comfort levels among preterm infants born at 28-32 weeks' gestation who were hospitalized in the neonatal intensive care unit during long-term follow-up while implementing a light-dark cycle.

DESIGN AND METHODS

This is a randomized controlled study conducted with the support of a day-night cycle in premature infants born at 28-32 weeks' gestation and admitted to the neonatal intensive care unit of a teaching and research hospital affiliated with the Ministry of Health. The study compared the follow-up results from hospitalization to discharge over a period of 8 weeks.

RESULTS

50% of premature infants admitted to the unit are multiple pregnancies. There was no significant difference in discharge weight, comfort level, pain level, vital signs of the infants included in the study (p > 0.05). The optimal development of infant feeding patterns was examinedand it was observed that the study group had significantly improved before the control group in terms of the time to switch to full enteral feeding and oral feeding (p < 0,05). The daily weight gain of the babies was examined, it was seen that the weight gain was higher in the study group compared to the control group (p < 0,05). The mean duration of hospitalization was compared, it was seen that the babies in the study group were discharged significantly earlier (p < 0,05).

CONCLUSION

The study compared the long-term outcomes of premature babies hospitalized in neonatal intensive care and babies exposed to a light-dark cycle and regularly monitored in standard care. The results showed that the babies in the study group had higher daily weight gain and were discharged earlier than the control group. There were also no statistically significant differences in comfort and pain scores, vital signs or oxygen saturation between the study and control groups.

PRACTICE IMPLICATIONS

A light-dark cycle was found to be a feasible and promising intervention for infants at 28-32 weeks' gestation. It was a nurse-led management of care that could be integrated into the usual care of 28-32-week-old babies in neonatal units.

Melatonin in Human Breast Milk and Its Potential Role in Circadian Entrainment: A Nod towards Chrononutrition?

Breastfeeding is the most appropriate source of a newborn's nutrition; among the plethora of its benefits, its modulation of circadian rhythmicity with melatonin as a potential neuroendocrine transducer has gained increasing interest. Transplacental transfer assures melatonin provision for the fetus, who is devoid of melatonin secretion. Even after birth, the neonatal pineal gland is not able to produce melatonin rhythmically for several months (with an even more prolonged deficiency following preterm birth). In this context, human breast milk constitutes the main natural source of melatonin: diurnal dynamic changes, an acrophase early after midnight, and changes in melatonin concentrations according to gestational age and during the different stages of lactation have been reported. Understudied thus far are the factors impacting on (changes in) melatonin content in human breast milk and their clinical significance in chronobiological adherence in the neonate: maternal as well as environmental aspects have to be investigated in more detail to guide nursing mothers in optimal feeding schedules which probably means a synchronized instead of mistimed feeding practice. This review aims to be thought-provoking regarding the critical role of melatonin in chrononutrition during breastfeeding, highlighting its potential in circadian entrainment and therefore optimizing (neuro)developmental outcomes in the neonatal setting.

Interorgan rhythmicity as a feature of healthful metabolism

The finding that animals with circadian gene mutations exhibit diet-induced obesity and metabolic syndrome with hypoinsulinemia revealed a distinct role for the clock in the brain and peripheral tissues. Obesogenic diets disrupt rhythmic sleep/wake patterns, feeding behavior, and transcriptional networks, showing that metabolic signals reciprocally control the clock. Providing access to high-fat diet only during the sleep phase (light period) in mice accelerates weight gain, whereas isocaloric time-restricted feeding during the active period enhances energy expenditure due to circadian induction of adipose thermogenesis. This perspective focuses on advances and unanswered questions in understanding the interorgan circadian control of healthful metabolism.