Newborns at risk of COVID-19, the story continues.

After more than 4 years of the SARS-CoV-2 pandemic, a great deal of knowledge on how this virus affects pregnant women, the fetus and the newborn has accumulated. Guidelines for mode of delivery, cord clamping, skin to skin, breastfeeding, and rooming-in have become uniform across the world. Vaccination has considerably improved outcomes, but hesitancy amongst pregnant patients and the emergence of variants remain challenged and SARS-CoV-2 positivity during pregnancy continues to be associated with an increased risk of maternal complications, premature delivery and higher neonatal mortality and morbidity. An emerging body of data now exists on the effect of SARS-CoV-2 in pregnancy on early neonatal outcomes, medical education in obstetrics and pediatrics, and longer-term developmental outcomes. In this article, we review the development in this field since our last review.

Gene expression in the intestine of newborn piglets after hypoxia-reoxygenation.

BACKGROUND: In preterm infants, intestinal hypoxia may partly contribute to the pathophysiology of necrotizing enterocolitis through changes in gene expression. Splanchnic hypoxia can be detected with monitoring of regional splanchnic oxygen saturation (rsSO2). Using a piglet model of asphyxia, we aimed to correlate changes in rsSO2 to gene expression. METHODS: Forty-two newborn piglets were randomized to control or intervention groups. Intervention groups were subjected to hypoxia until they were acidotic and hypotensive. Next, they were reoxygenated for 30 min according to randomization, i.e., 21% O2, 100% O2, or 100% O2 for 3 min followed by 21% O2, and observed for 9 h. We continuously measured rsSO2 and calculated mean rsSO2 and variability of rsSO2 (rsCoVar = SD/mean). Samples of terminal ileum were analyzed for mRNA expression of selected genes related to inflammation, erythropoiesis, fatty acid metabolism, and apoptosis. RESULTS: The expression of selected genes was not significantly different between control and intervention groups. No associations between mean rsSO2 and gene expression were observed. However, lower rsCoVar was associated with the upregulation of apoptotic genes and the downregulation of inflammatory genes (P < 0.05). CONCLUSION: Our study suggests that hypoxia and reoxygenation cause reduced vascular adaptability, which seems to be associated with the upregulation of apoptosis and downregulation of inflammation. IMPACT: Our results provide important insight into the (patho)physiological significance of changes in the variability of rsSO2. Our findings may advance future research and clinical practice regarding resuscitation strategies of preterm infants.

Splanchnic oxygen saturation during reoxygenation with 21% or 100% O2 in newborn piglets.

BACKGROUND: Increasing evidence recognizes the harm of excess oxygen to lungs, eyes, and brain of preterm infants, but not yet to the intestine. We assessed changes in splanchnic oxygenation during reoxygenation with 21% compared to 100% O2 in a newborn piglet model of perinatal asphyxia. METHODS: We randomized 25 piglets to control or intervention. Intervention groups underwent global hypoxia until acidosis and hypotension occurred. Piglets were reoxygenated for 30 min with 21% or 100% O2 and observed for 9 h. We continuously measured regional splanchnic oxygen saturation (rsSO2) using near-infrared spectroscopy (NIRS). We calculated mean rsSO2 and rsCoVar (as SD/mean). We measured PaO2 and SaO2, sampled from the right carotid artery. RESULTS: Reoxygenation after global hypoxia restored rsSO2. Reoxygenation with 100% O2 increased rsSO2 to values significantly higher than baseline. In intervention groups, rsCoVar decreased during observation compared to baseline. We found a correlation between rsSO2 and PaO2 (r = 0.420, P < 0.001) and between rsSO2 and SaO2 (r = 0.648, P < 0.001) in pooled data from the entire experiment. CONCLUSION: Reoxygenation after global hypoxia improves splanchnic oxygenation, but is associated with reduced variability of rsSO2. Reoxygenation with 100% O2 exposes the intestine to hyperoxia. Splanchnic NIRS is able to detect intestinal hypoxia and hyperoxia. IMPACT: Splanchnic oxygenation improves during reoxygenation after global hypoxia, though reoxygenation with 100% O2 exposes the intestine to hyperoxia. Decreased variability of splanchnic oxygenation several hours after hypoxia and reoxygenation seems to be independent of the resuscitation strategy, and may indicate intestinal injury. Splanchnic NIRS monitoring was able to detect intestinal hypoxia and exposure to hyperoxia, as evidenced by a strong correlation between splanchnic oxygenation and arterial oxygen content.

Fine mapping of the major histocompatibility complex (MHC) in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) suggests involvement of both HLA class I and class II loci.

The etiology of myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is unknown, but involvement of the immune system is one of the proposed underlying mechanisms. Human leukocyte antigen (HLA) associations are hallmarks of immune-mediated and autoimmune diseases. We have previously performed high resolution HLA genotyping and detected associations between ME/CFS and certain HLA class I and class II alleles. However, the HLA complex harbors numerous genes of immunological importance, and there is extensive and complex linkage disequilibrium across the region. In the current study, we aimed to fine map the association signals in the HLA complex by genotyping five additional classical HLA loci and 5,342 SNPs in 427 Norwegian ME/CFS patients, diagnosed according to the Canadian Consensus Criteria, and 480 healthy Norwegian controls. SNP association analysis revealed two distinct and independent association signals (p ≤ 0.001) tagged by rs4711249 in the HLA class I region and rs9275582 in the HLA class II region. Furthermore, the primary association signal in the HLA class II region was located within the HLA-DQ gene region, most likely due to HLA-DQB1, particularly the amino acid position 57 (aspartic acid/alanine) in the peptide binding groove, or an intergenic SNP upstream of HLA-DQB1. In the HLA class I region, the putative causal locus might map outside the classical HLA genes as the association signal spans several genes (DDR1, GTF2H4, VARS2, SFTA2 and DPCR1) with expression levels influenced by the ME/CFS associated SNP genotype. Taken together, our results implicate the involvement of the MHC, and in particular the HLA-DQB1 gene, in ME/CFS. These findings should be replicated in larger cohorts, particularly to verify the putative involvement of HLA-DQB1, a gene important for antigen-presentation to T cells and known to harbor alleles providing the largest risk for well-established autoimmune diseases.

A critical review of the 2020 International Liaison Committee on Resuscitation treatment recommendations for resuscitating the newly born infant.

The 2020 recommendations from the International Liaison Committee on Resuscitation are an improved version of the 2015 version. The algorithm and 15 procedures are unchanged from 2015, but there are six procedures with new or changed recommendations. One new recommendation is briefing/debriefing following neonatal resuscitation. Procedures with changed suggestions/recommendations are as follows: suctioning of non-vigorous infants delivered through meconium-stained amniotic fluid, sustained inflation of preterm infants, optimising epinephrine (adrenaline), vascular access and discontinuing resuscitative efforts. CONCLUSION: In this review, we summarise the present recommendations and offer additional comments and views regarding heart rate detection, cord clamping, oxygenation and thermal control.

Oxygen for the delivery room respiratory support of moderate-to-late preterm infants. An international survey of clinical practice from 21 countries.

AIM: The aim of this study was to determine clinician opinion regarding oxygen management in moderate-late preterm resuscitation. METHODS: An anonymous online questionnaire was distributed through email/social messaging platforms to neonatologists in 21 countries (October 2020-March 2021) via REDCap. RESULTS: Of the 695 respondents, 69% had access to oxygen blenders and 90% had pulse oximeters. Respondents from high-income countries were more likely to have oxygen blenders than those from middle-income countries (72% vs. 66%). Most initiated respiratory support with FiO2 0.21 (43%) or 0.3 (36%) but only 45% titrated FiO2 to target SpO2 . Most (89%) considered heart rate as a more important indicator of response than SpO2 . Almost all (96%) supported the need for well-designed trials to examine oxygenation in moderate-late preterm resuscitation. CONCLUSION: Most clinicians resuscitated moderate-late preterm infants with lower initial FiO2 but some cannot/will not target SpO2 or titrate FiO2 . Most consider heart rate as a more important indicator of infant response than SpO2 .Large and robust clinical trials examining oxygen use for moderate-late preterm resuscitation, including long-term neurodevelopmental outcomes, are supported amongst clinicians.

Evaluating preterm care across Europe using the eNewborn European Network database.

BACKGROUND: The inefficiency of recording data repeatedly limits the number of studies conducted. Here we illustrate the wider use of data captured as part of the European eNewborn benchmarking programme. METHODS: We extracted data on 39,529 live-births from 22 weeks 0 days to 31 weeks 6 days gestational age (GA) or ≤1500 g birth weight. We explored relationships between delivery room care and Apgar scores on mortality and bronchopulmonary dysplasia (BPD) and calculated the time needed for each country to detect a clinically relevant change in these outcomes following a hypothetical intervention. RESULTS: Early neonatal, neonatal, and in-hospital mortality were 3.90% (95% CI 3.71, 4.09), 6.00% (5.77, 6.24) and 7.57% (7.31, 7.83), respectively. The odds of death were greater with decreasing GA, lower Apgar scores, growth restriction, male sex, multiple birth and no antenatal steroids. Relationships for BPD were similar. The time required for participating countries to achieve 80% power to detect a relevant change in outcomes following a hypothetical intervention in 23-25 weeks' GA infants ranged from 12 years for neonatal mortality and 22 years for BPD compared to 1 year for the whole network. CONCLUSIONS: The eNewborn platform offers opportunity to drive efficiencies in benchmarking, quality control and research.

Delivery room handling of the newborn.

For newly born babies, especially those in need of intervention at birth, actions taken during the first minute after birth, the so-called "Golden Minute", can have important implications for long-term outcomes. Both delivery room handling, including identification of maternal and infant risk factors and provision of effective resuscitation interventions, and antenatal care decisions regarding antenatal steroid administration and mode of delivery, are important and can affect outcomes. Anticipating risk factors for neonates at high risk of requiring resuscitation can decrease time to resuscitation and improve the prognosis. Following a review of maternal and fetal risk factors affecting newborn resuscitation, we summarize the current recommendations for delivery room handling of the newborn. This includes recommendations and rationale for the use of delayed cord clamping and cord milking, heart rate assessment [including the use of electrocardiogram (ECG) electrodes in the delivery room], role of suctioning in newborn resuscitation, and the impact of various ventilatory modes. Oxygenation should be monitored by pulse oximetry. Effects of oxygen and surfactant on subsequent pulmonary outcomes, and recommendations for provisions of appropriate thermoregulatory support are discussed. Regular teaching of delivery room handling should be mandatory.

Preterm Infant Outcomes after Randomization to Initial Resuscitation with FiO2 0.21 or 1.0.

OBJECTIVE: To determine rates of death or neurodevelopmental impairment (NDI) at 2 years corrected age (primary outcome) in children <32 weeks' gestation randomized to initial resuscitation with a fraction of inspired oxygen (FiO2) value of 0.21 or 1.0. STUDY DESIGN: Blinded assessments were conducted at 2-3 years corrected age with the Bayley Scales of Infant and Toddler Development, Third Edition or the Ages and Stages Questionnaire by intention to treat. RESULTS: Of the 290 children enrolled, 40 could not be contacted and 10 failed to attend appointments. Among the 240 children for whom outcomes at age 2 years were available, 1 child had a lethal congenital anomaly, 1 child had consent for follow-up withdrawn, and 23 children died. The primary outcome, which was available in 238 (82%) of those randomized, occurred in 47 of the 117 (40%) children assigned to initial FiO2 0.21 and in 38 of the 121 (31%) assigned to initial FiO2 1.0 (OR, 1.47; 95% CI, 0.86-2.5; P = .16). No difference in NDI was found in 215 survivors randomized to FiO2 0.21 vs 1.0 (OR, 1.26; 95% CI, 0.70-2.28; P = .11). In post hoc exploratory analyses in the whole cohort, children with a 5-minute blood oxygen saturation (SpO2) <80% were more likely to die or to have NDI (OR, 1.85; 95% CI, 1.07-3.2; P = .03). CONCLUSIONS: Initial resuscitation of infants <32 weeks' gestation with initial FiO2 0.21 had no significant effect on death or NDI compared with initial FiO2 1.0. Further evaluation of optimum initial FiO2, including SpO2 targeting, in a large randomized controlled trial is needed. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Network Registry ACTRN 12610001059055 and the National Malaysian Research Registry NMRR-07-685-957.

Prospective plasma proteome changes in preterm infants with different gestational ages.

BACKGROUND: In this study, we aimed to analyze time-resolved plasma proteome changes in preterm neonates stratified by their gestational age to detect malfunctioning pathways that derive from the systemic immaturity of the neonate and to highlight those that are differentially regulated during the early development. METHODS: Preterm newborns were enrolled in three subgroups with different gestational ages: before 26 weeks of gestation (group 1), between 27 and 28 weeks of gestation (group 2), and between 29 and 30 (group 3) weeks of gestation. Plasma protein abundances were assessed at two time points (at preterm delivery and at the 36th week of post-menstrual age) by quantitative proteomics. RESULT: The quantitative analysis of plasma proteome in preterm infants revealed a multitude of time-related differences in protein abundances between the studied groups. We report protein changes in several functional domains, including inflammatory domains, immunomodulatory factors, and coagulation regulators as key features, with important gestational age-dependent hemopexin induction. CONCLUSION: The global trend emerging from our data, which can collectively be interpreted as a progression toward recovery from the perinatal perturbations, highlights the profound impact of gestation duration on the ability to bridge the gap in systemic homeostasis after preterm labor.

Oxygen and preterm infant resuscitation: what else do we need to know?

PURPOSE OF REVIEW: To evaluate current evidence for the use of lower or higher oxygen strategies for preterm infant resuscitation RECENT FINDINGS: The equipoise for using higher fraction of inspired oxygen (FiO2) (>0.4) to initiate preterm infant respiratory stabilization has been lost. Recent meta-analyses of randomized controlled trials assessing outcomes after using higher (FiO2 ≥ 0.6) vs. lower (FiO2 ≤ 0.3) oxygen strategies to initiate preterm resuscitation shows no difference in the rates of death or major morbidities. However, not achieving pulse oximetry saturations of at least 80% by 5 min of age, whether it was due to iatrogenic oxygen insufficiency or poor infant pulmonary function, was associated with lower heart rates (mean difference -8.37, 95% confidence interval: -15.73, -1.01) and major intraventricular hemorrhage. There remains scarce neurodevelopmental data in this area and information about the impact of oxygen targeting strategies in low resourced areas. These knowledge gaps are research priorities that must be addressed in large, well designed randomized controlled trials. SUMMARY: Most clinicians now use lower oxygen strategies to initiate respiratory support for all infants, including preterm infants with significant lung disease. However, the impact of such strategies, particularly for neurodevelopmental outcomes and for lower resourced areas, remains uncertain and must be urgently addressed.

Comparison of whole genome expression profile between preterm and full-term newborns.

OBJECTIVES: Evaluate the time dependent expression of genes in preterm neonates and verify the influence of ontogenic maturation and the environmental factors on the gene expression after birth. MATERIAL AND METHODS: The study was carried out on 20 full-term newborns and 62 preterm newborns (mean birth weight = 1002 [g] (SD: 247), mean gestational age = 27.2 weeks (SD: 1.9)). Blood samples were drawn from all the study participants at birth and at the 36th week postmenstrual age from the preterm group to assess whole genome expression in umbilical cord blood and in peripheral blood leukocytes, respectively. (SurePrint G3 Human Gene Expression v3, 8x60K Microarrays (Agilent)). RESULTS: A substantial number of genes was found to be expressed differentially at the time of birth and at 36 PMA in comparison to the term babies with more genes being down-regulated than up-regulated. However, the fold change in the majority of cases was < 2.0. Extremely preterm and very preterm infants were characterized by significantly down-regulated cytokine and chemokine related pathways. The number of down-regulated genes decreased and number of up-regulated genes increased at 36 PMA vs. cord blood. There were no specific gene expression pathway profiles found within the groups of different gestational ages. CONCLUSIONS: Preterm delivery is associated with a different gene expression profile in comparison to term delivery. The gene expression profile changes with the maturity of a newborn measured by the gestational age.

Clinicians in 25 countries prefer to use lower levels of oxygen to resuscitate preterm infants at birth.

AIM: This study determined current international clinical practice and opinions regarding initial fractional inspired oxygen (FiO2 ) and pulse oximetry (SpO2 ) targets for delivery room resuscitation of preterm infants of less than 29 weeks of gestation. METHODS: An online survey was disseminated to neonatal clinicians via established professional clinical networks using a web-based survey programme between March 9 and June 30, 2015. RESULTS: Of the 630 responses from 25 countries, 60% were from neonatologists. The majority (77%) would target SpO2 between the 10th to 50th percentiles values for full-term infants. The median starting FiO2 was 0.3, with Japan using the highest (0.4) and the UK using the lowest (0.21). New Zealand targeted the highest SpO2 percentiles (median 50%). Most respondents agreed or did not disagree that a trial was required that compared the higher FiO2 of 0.6 (83%), targeting the 50th SpO2 percentile (60%), and the lower FiO2 of 0.21 (80%), targeting the 10th SpO2 percentile (78%). Most (65%) would join this trial. Many considered that evidence was lacking and further research was needed. CONCLUSION: Clinicians currently favour lower SpO2 targets for preterm resuscitation, despite acknowledging the lack of evidence for benefit or harm, and 65% would join a clinical trial.

Transcriptome profiling of the newborn mouse brain after hypoxia-reoxygenation: hyperoxic reoxygenation induces inflammatory and energy failure responsive genes.

BACKGROUND: Supplemental oxygen used during resuscitation can be detrimental to the newborn brain. The aim was to determine how different oxygen therapies affect gene transcription in a hypoxia-reoxygenation model. METHODS: C57BL/6 mice (n = 56), postnatal day 7, were randomized either to 120 min of hypoxia 8% O2 followed by 30 min of reoxygenation with 21, 40, 60, or 100% O2, or to normoxia followed by 30 min of 21 or 100% O2. Affymetrix 750k expression array was applied with RT-PCR used for validation. Histopathology and immunohistochemistry 3 d after hypoxia-reoxygenation compared groups reoxygenated with 21 or 100% O2 with normoxic controls (n = 22). RESULTS: In total, ~81% of the gene expression changes were altered in response to reoxygenation with 60 or 100% O2 and constituted many inflammatory-responsive genes (i.e., C5ar2, Stat3, and Ccl12). Oxidative phosphorylation was downregulated after 60 or 100% O2. Iba1(+) cells were significantly increased in the striatum and hippocampal CA1 after both 21 and 100% O2. CONCLUSION: In the present model, hypoxia-reoxygenation induces microglial accumulation in subregions of the brain. The transcriptional changes dominating after applying hyperoxic reoxygenation regimes include upregulating genes related to inflammatory responses and suppressing the oxidative phosphorylation pathway.

Endonuclease VIII-like 3 (Neil3) DNA glycosylase promotes neurogenesis induced by hypoxia-ischemia.

Neural stem/progenitor cell proliferation and differentiation are required to replace damaged neurons and regain brain function after hypoxic-ischemic events. DNA base lesions accumulating during hypoxic-ischemic stress are removed by DNA glycosylases in the base-excision repair pathway to prevent cytotoxicity and mutagenesis. Expression of the DNA glycosylase endonuclease VIII-like 3 (Neil3) is confined to regenerative subregions in the embryonic and perinatal brains. Here we show profound neuropathology in Neil3-knockout mice characterized by a reduced number of microglia and loss of proliferating neuronal progenitors in the striatum after hypoxia-ischemia. In vitro expansion of Neil3-deficient neural stem/progenitor cells revealed an inability to augment neurogenesis and a reduced capacity to repair for oxidative base lesions in single-stranded DNA. We propose that Neil3 exercises a highly specialized function through accurate molecular repair of DNA in rapidly proliferating cells.