A Systematic Review of the Effects of Skin-to-Skin Contact on Biomarkers of Stress in Preterm Infants and Parents.

BACKGROUND: Premature infants and their parents experience significant stress related to separation and lifesaving procedures. While evidence suggests that skin-to-skin contact (SSC) is a stress-reducing intervention for both neonates and parents, the mechanisms that underlie its efficacy are not well understood. OBJECTIVE: Purpose of this systematic review is to summarize the current state of knowledge on changes in biomarkers (ie, oxytocin [OT], cortisol, hypoxanthine, xanthine, uric acid, and allantoin), associated with SSC in premature infants and parents, that may reflect physiologic responses to stress. METHODS: A comprehensive literature search was conducted from 1990 to 2020. Studies were selected using prespecified inclusion and exclusion criteria. RESULTS: Of the 175 studies identified, only 19 are included in this review. Ten studies evaluated only infants, 2 evaluated only parents, and 7 evaluated for changes in biomarkers in both infants and parents. Cortisol was the most common biomarker evaluated. While changes in infants' cortisol levels were highly variable, in 55% of the parent studies, parent cortisol levels decreased following SSC. In both parents and infants, OT levels decreased following SSC. Only 1 study found that allantoin levels were significantly lower in infants who received SSC. IMPLICATIONS FOR PRACTICE AND RESEARCH: While evidence suggests the numerous benefits of SSC, additional research is needed to identify the optimal biomarker to determine the mechanisms that underlie these effects. The use of novel biomarkers (eg, gene expression changes microbiome) may provide new insights into the mechanisms that underlie the efficacy of SSC.Video Abstract available at:https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=48.

Oxidative Stress Biomarker Decreased in Preterm Neonates Treated With Kangaroo Mother Care.

OBJECTIVE: Due to physiological and metabolic immaturity, prematurely born infants are at increased risk because of maternal separation in many neonatal intensive care units (NICUs). The stress induced from maternal-infant separation can lead to well-documented short-term physiologic instability and potentially lifelong neurological, sociological, or psychological sequelae. Based on previous studies of kangaroo mother care (KMC) that demonstrated improvement in physiologic parameters, we examined the impact of KMC on physiologic measures of stress (abdominal temperature, heart rate, oxygen saturation, perfusion index, near-infrared spectrometry), oxidative stress, and energy utilization/conservation in preterm infants. METHODS: In this randomized, stratified study of premature neonates, we compared the effects on urinary concentrations of biomarkers of energy utilization and oxidative stress of 1 hr of KMC versus incubator care on Day 3 of life in intervention-group babies (n = 26) and control-group babies (n = 25), respectively. On Day 4, both groups received 1 hr of KMC. Urinary samples were collected 3 hr before and 3 hr after intervention/incubator care on both days. Energy utilization was assessed by measures of adenosine triphosphate (ATP) degradation (i.e., hypoxanthine, xanthine, and uric acid). Oxidative stress was assessed using urinary allantoin. Mixed-models analysis was used to assess differences in purine/allantoin. RESULTS: Mean allantoin levels over Days 3 and 4 were significantly lower in the KMC group than in the control group (p = .026). CONCLUSIONS: Results provide preliminary evidence that KMC reduces neonatal oxidative stress processes and that urinary allantoin could serve as an effective noninvasive marker for future studies.

Oral dextrose reduced procedural pain without altering cellular ATP metabolism in preterm neonates: a prospective randomized trial.

OBJECTIVE: To examine the effects of 30% oral dextrose on biochemical markers of pain, adenosine triphosphate (ATP) degradation, and oxidative stress in preterm neonates experiencing a clinically required heel lance. STUDY DESIGN: Utilizing a prospective study design, preterm neonates that met study criteria (n = 169) were randomized to receive either (1) 30% oral dextrose, (2) facilitated tucking, or (3) 30% oral dextrose and facilitated tucking 2 min before heel lance. Plasma markers of ATP degradation (hypoxanthine, uric acid) and oxidative stress (allantoin) were measured before and after the heel lance. Pain was measured using the premature infant pain profile-revised (PIPP-R). RESULTS: Oral dextrose, administered alone or with facilitated tucking, did not alter plasma markers of ATP utilization and oxidative stress. CONCLUSION: A single dose of 30% oral dextrose, given before a clinically required heel lance, decreased signs of pain without increasing ATP utilization and oxidative stress in premature neonates.