Antepartum and intrapartum factors preceding neonatal hypoxic-ischemic encephalopathy

Magnesium sulfate and risk of hypoxic-ischemic encephalopathy in a high-risk cohort

BACKGROUND

Hypoxic-ischemic encephalopathy contributes to morbidity and mortality among neonates ≥36 weeks of gestation. Evidence of preventative antenatal treatment is limited. Magnesium sulfate has neuroprotective properties among preterm fetuses. Hypertensive disorders of pregnancy are a risk factor for hypoxic-ischemic encephalopathy, and magnesium sulfate is recommended for maternal seizure prophylaxis among patients with preeclampsia with severe features.

OBJECTIVE

(1) Determine trends in the incidence of hypertensive disorders of pregnancy, antenatal magnesium sulfate, and hypoxic-ischemic encephalopathy; (2) evaluate the association between hypertensive disorders of pregnancy and hypoxic-ischemic encephalopathy; and (3) evaluate if, among patients with hypertensive disorders of pregnancy, the odds of hypoxic-ischemic encephalopathy is mitigated by receipt of antenatal magnesium sulfate.

STUDY DESIGN

We analyzed a prospective cohort of live births ≥36 weeks of gestation between 2012 and 2018 within the California Perinatal Quality Care Collaborative registry, linked with the California Department of Health Care Access and Information files. We used Cochran-Armitage tests to assess trends in hypertensive disorders, encephalopathy diagnoses, and magnesium sulfate utilization and compared demographic factors between patients with or without hypertensive disorders of pregnancy or treatment with magnesium sulfate. Hierarchical logistic regression models were built to explore if hypertensive disorders of pregnancy were associated with any severity and moderate/severe hypoxic-ischemic encephalopathy. Separate hierarchical logistic regression models were built among those with hypertensive disorders of pregnancy to evaluate the association of magnesium sulfate with hypoxic-ischemic encephalopathy.

RESULTS

Among 44,314 unique infants, the diagnosis of hypoxic-ischemic encephalopathy, maternal hypertensive disorders of pregnancy, and the use of magnesium sulfate increased over time. Compared with patients with hypertensive disorders of pregnancy alone, patients with hypertensive disorders treated with magnesium sulfate represented a high-risk population. They were more likely to be publicly insured, born between 36 and 38 weeks of gestation, be small for gestational age, have lower Apgar scores, require a higher level of resuscitation at delivery, have prolonged rupture of membranes, experience preterm labor and fetal distress, and undergo operative delivery (all P<.002). Hypertensive disorders of pregnancy were associated with hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.13-1.40]; P<.001) and specifically moderate/severe hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.11-1.42]; P<.001). Among patients with hypertensive disorders of pregnancy, treatment with magnesium sulfate was associated with 29% reduction in the odds of neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.71 [95% confidence interval, 0.52-0.97]; P=.03) and a 37% reduction in the odds of moderate/severe neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.63 [95% confidence interval, 0.42-0.94]; P=.03).

CONCLUSION

Hypertensive disorders of pregnancy are associated with hypoxic-ischemic encephalopathy and, specifically, moderate/severe disease. Among people with hypertensive disorders, receipt of antenatal magnesium sulfate is associated with a significant reduction in the odds of hypoxic-ischemic encephalopathy and moderate/severe disease in a neonatal cohort admitted to neonatal intensive care unit at ≥36 weeks of gestation. The findings of this observational study cannot prove causality and are intended to generate hypotheses for future clinical trials on magnesium sulfate in term infants.

Hypoxic-ischaemic encephalopathy code: A systematic review for resource-limited settings

It is estimated that 96% of infants with hypoxic-ischaemic encephalopathy (HIE) are born in resource-limited settings with no capacity to provide the standard of care that has been established for nearly 15 years in high-resource countries, which includes therapeutic hypothermia (TH), continuous electroencephalographic monitoring and magnetic resonance imaging (MRI) in addition to close vital signs and haemodynamic monitoring. This situation does not seem to be changing; however, even with these limitations, currently available knowledge can help improve the care of HIE patients in resource-limited settings. The purpose of this systematic review was to provide, under the term "HIE Code", evidence-based recommendations for feasible care practices to optimise the care of infants with HIE and potentially help reduce the risks associated with comorbidity and improve neurodevelopmental outcomes. The content of the HIE code was grouped under 9 headings: (1) prevention of HIE, (2) resuscitation, (3) first 6h post birth, (4) identification and grading of encephalopathy, (5) seizure management, (6) other therapeutic interventions, (7) multiple organ dysfunction, (8) diagnostic tests and (9) family care.

Correlation analysis between the amniotic fluid contamination and clinical grading of neonatal hypoxic-ischemic encephalopathy and biomarkers of brain damage

BACKGROUND

Amniotic fluid contamination (AFC) is a risk factor for neonatal hypoxic ischemic encephalopathy (HIE); however, the correlation between AFC level and the incidence and clinical grading of HIE, in addition to relevant biomarkers of brain damage, have not been assessed.

METHODS

This single-center observational study included 75 neonates with moderate-to-severe HIE. The neonates with HIE were divided into four subgroups according to the AFC level: normal amniotic fluid with HIE group (NAF-HIE), I°AFC with HIE group (I°AFC-HIE), II°AFC with HIE group (II°AFC-HIE), and III°AFC with HIE group (III°AFC-HIE). The control groups consisted of 35 healthy neonates. The clinical grading of neonatal HIE was performed according to the criteria of Sarnat and Sarnat. Serum tau protein and S100B were detected by enzyme-linked immunosorbent assay kits. Correlations of serum tau protein and S100B were evaluated using the Pearson correlation analysis.

RESULTS

(1) The incidence of neonatal HIE in the NAF-HIE group was 20 cases (26. 7%), I°AFC-HIE was 13 cases (17.3%), II°AFC-HIE was 10 cases (13.3%), and III°AFC-HIE was 32 cases (42. 7%). The incidence of moderate-to-severe HIE in the I°-III°AFC-HIE groups was 73.3% (55/75). (2) In 44 cases with severe HIE, 26 cases (59.1%) occurred in the III°AFC-HIE group, which had a significantly higher incidence of severe HIE than moderate HIE (p < 0.05). In NAF-HIE and I°AFC-HIE groups, the incidence of moderate HIE was 45.2% and 29.0%, respectively, which was higher than that of severe HIE (X2 = 9.2425, p < 0.05; X2 = 5.0472, p < 0.05, respectively). (3) Serum tau protein and S100B levels in the HIE groups were significantly higher than in the control group (all p < 0.05), and were significantly higher in the III°AFC-HIE group than in the NAF-HIE and I°AFC-HIE groups (all p < 0.05). (4) Serum tau protein and S100B levels in the severe HIE group were significantly higher in the moderate HIE group (all p < 0.05). (5) Serum tau protein and S100B levels were significantly positively correlated (r = 0.7703, p < 0.0001).

CONCLUSION

Among children with severe HIE, the incidence of III°AFC was higher, and the levels of serum tau protein and S100B were increased. AFC level might be associated with HIE grading.

The Placenta and Neonatal Encephalopathy with a Focus on Hypoxic-Ischemic Encephalopathy

Background: Placental examination is important for its diagnostic immediacy to correlate with maternal and/or fetal complications and parturitional difficulties. In a broader context, clinicopathologic studies of the placenta have addressed a range of pathogenetic questions that have led to conclusive and inconclusive results and interpretations. Methods: Recent standardized morphologic criteria and terminology of placental lesions have facilitated the ability to compare findings from studies that have focused on complications and outcomes of pregnancy. This review is an evaluation of recent studies on placental lesions associated with hypoxic-ischemic encephalopathy (HIE). Conclusion: No apparent consensus exists on whether it is fetal inflammation with the release of cytokines or chronic maternal and/or fetal vascular malperfusion is responsible for HIE with a lowering of the threshold for hypoxic ischemia. The counter argument is that HIE occurs solely as an intrapartum event. Additional investigation is necessary.

The association of placental pathology and neurodevelopmental outcomes in patients with neonatal encephalopathy

BACKGROUND

Studies conflict on how acute versus chronic placental pathology impacts outcomes after neonatal encephalopathy from presumed hypoxic-ischemic encephalopathy (HIE). We examine how outcomes after presumed HIE vary by placental pathology categories.

METHODS

We performed retrospective chart review for neonates with presumed HIE, regardless of severity, focusing on 50 triads for whom placental specimens were available for re-review. Placentas were categorized as having only acute, any chronic, or no lesions. Primary outcomes included in-hospital morbidity/mortality and long-term neurodevelopmental symptoms. Secondary outcomes assessed neonatal MRI and EEG.

RESULTS

Demographics did not differ between groups. Forty-seven neonates were treated with therapeutic hypothermia. Placental acuity category was not associated with primary or secondary outcomes, but clinical and/or histopathological chorioamnionitis was associated with abnormal EEG background and post-neonatal epilepsy (16.7%, n = 3 with chorioamnionitis versus 0%, n = 0 without chorioamnionitis, p = 0.04).

CONCLUSIONS

When grouped by acute, chronic, or absent placental lesions, we observed no association with in-hospital, neurodevelopmental, MRI, or EEG outcomes. When reanalyzed by the presence of chorioamnionitis, we found that chorioamnionitis appeared to be associated with a higher risk of EEG alterations and post-neonatal epilepsy. Despite our limited sample size, our results emphasize the critical role of placental examination for neuroprognostication in presumed HIE.

IMPACT

Neonatal encephalopathy presumed to result from impaired fetal cerebral oxygenation or blood flow is called hypoxic ischemic encephalopathy (HIE). Prior studies link placental pathology to various outcomes after HIE but disagree on the impact of acute versus chronic pathology. Our study determines that neurodevelopmental outcomes, in-hospital outcomes, injury on MRI, and EEG findings in patients with HIE are not differentially associated with acute versus chronic placental pathology. Chorioamnionitis is associated with an increased risk of abnormal EEG patterns and post-neonatal epilepsy. Histopathologic chorioamnionitis without clinical symptoms is common in HIE, emphasizing the crucial role of placental pathology for neuroprognostication.

Association of maternal, fetal and labor variables with a low Apgar score in the fifth minute in term pregnancy: a case-control study

PURPOSE

To search for maternal, labor-related and fetal variables associated with low Apgar in the fifth minute in term pregnancy.

METHODS

A retrospective case-control study with term births was conducted in a public teaching hospital from 2013 to 2020. Cases were term births with Apgar score less than 7 in the fifth minute, and controls, the next one or two births following a case, with Apgar of 7 or more. Non-cephalic presentations, multiples and malformations were excluded. We accessed 100 cases and 190 controls. We considered significant values of p < 0.05.

RESULTS

Were accessed 27 variables which could be risk factors, from which 12 were associated with the outcome. We found a protective effect of prelabor cesarean for the outcome, odds ratio (OR) 0.38, p = 0.013. Consequently, we conducted two sets of analyses: in the whole group and in the group of laboring women. The values of OR were in general greater in the group of laboring women, compared with the whole group. We conducted multivariate analysis within the group of women in labor. The variables which fitted best in the model were nulliparity, male sex of the fetus, less than six prenatal visits and abnormal cardiotocography; all remained significant. An association of rupture of membranes more than 360 min with the outcome, even after controlling fpr duration of labor, was found; adjusted OR 2.45, p = 0.023.

CONCLUSION

Twelve variables were associated with the outcome. Prelabor cesarean had a protective effect. The time of ruptured membranes was associated with low Apgar.

Placental Histologic Abnormalities and 2-Year Outcomes in Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVE

We aimed to examine the association between placental abnormalities and neurodevelopmental outcomes in a multicenter cohort of newborn infants with hypoxic-ischemic encephalopathy (HIE) that underwent therapeutic hypothermia. We hypothesized that subjects with acute placental abnormalities would have reduced risk of death or neurodevelopmental impairment (NDI) at 2 years of age after undergoing therapeutic hypothermia compared to subjects without acute placental changes.

STUDY DESIGN

Among 500 subjects born at ≥36 weeks gestation with moderate or severe HIE enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, a placental pathologist blinded to clinical information reviewed clinical pathology reports to determine the presence of acute only, chronic only, or both acute and chronic histologic abnormalities. We calculated adjusted relative risks (aRRs) for associations between placental pathologic abnormalities and death or NDI at age 2 years, adjusting for HIE severity, treatment assignment, and site.

RESULT

321/500 subjects (64%) had available placental pathology reports. Placental abnormalities were characterized as acute only (20%), chronic only (21%), both acute and chronic (43%), and none (15%). The risk of death or NDI was not statistically different between subjects with and without an acute placental abnormality (46 vs. 53%, aRR 1.1, 95% confidence interval (CI): 0.9, 1.4). Subjects with two or more chronic lesions were more likely to have an adverse outcome than subjects with no chronic abnormalities, though this did not reach statistical significance (55 vs. 45%, aRR 1.24, 95% CI: 0.99, 1.56).

CONCLUSION

Placental pathologic findings were not independently associated with risk of death or NDI in subjects with HIE. The relationship between multiple chronic placental lesions and HIE outcomes deserves further study.

Meconium-stained amniotic fluid

Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.

Harnessing the therapeutic potential of the stem cell secretome in neonatal diseases

Preterm birth and intrapartum related complications account for a substantial amount of mortality and morbidity in the neonatal period despite significant advancements in neonatal-perinatal care. Currently, there is a noticeable lack of curative or preventative therapies available for any of the most common complications of prematurity including bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage, periventricular leukomalacia and retinopathy of prematurity or hypoxic-ischemic encephalopathy, the main cause of perinatal brain injury in term infants. Mesenchymal stem/stromal cell-derived therapy has been an active area of investigation for the past decade and has demonstrated encouraging results in multiple experimental models of neonatal disease. It is now widely acknowledged that mesenchymal stem/stromal cells exert their therapeutic effects via their secretome, with the principal vector identified as extracellular vesicles. This review will focus on summarizing the current literature and investigations on mesenchymal stem/stromal cell-derived extracellular vesicles as a treatment for neonatal diseases and examine the considerations to their application in the clinical setting.

Perinatal brain damage - what the obstetrician needs to know

Perinatal brain damage is still one of the leading contributors to perinatal death and postnatal disability worldwide. However, the term perinatal brain damage encompasses very different aetiological entities that result in an insult to the developing brain and does not differentiate between the onset, cause and severity of this insult. Hypoxic-ischemic encephalopathy (HIE), intraventricular haemorrhage, periventricular leukomalacia and perinatal stroke are often listed as the major aetiologies of perinatal brain damage. They differ by type and timing of injury, neuropathological and imaging findings and their clinical picture. Along the timeline of neurodevelopment in utero, there appears to be a specific "window of vulnerability" for each type of injury, but clinical overlap does exist. In the past, peripartum acute hypoxia was believed to be the major, if not the only, cause of perinatal brain damage, but intrauterine inflammation, prematurity, chronic hypoxia/growth retardation and genetic abnormalities appear to be at least equally important contributors.

Maternal and Fetal Risk Factors for Neonatal Hypoxic-Ischemic Encephalopathy: A Retrospective Study

Background

Neonatal hypoxic-ischemic encephalopathy (HIE) leads to different degree of neurological sequelae. The incidence of HIE is relatively high, and the risk factors associated with HIE are still controversial. It is necessary to identify the risk factors associated with HIE.

Methods

A total of 258 neonates (110 HIE patients and 148 controls) were enrolled in this study. The characteristics of pregnant women and fetuses during pregnancy and delivery were compared between HIE patients and controls, and the risk factors of HIE were analyzed.

Results

The proportions of premature infants, low-birth-weight infants and the levels of 1-minute Apgar score, 5-minute Apgar score in HIE group were significantly lower than those in control group, while the proportion of amniotic fluid contamination in the HIE group was significantly higher than those of the controls. When HIE was taken as the end point of 1-minute Apgar score, and 5-minute Apgar score, the cut-off value of 1-minute Apgar score was 3, and 5-minute Apgar score was 7 by receiver operating characteristic (ROC) curve analysis. The results of multivariate logistic regression analysis showed that low birth weight (<2.5 kg) (OR 1.780, 95% CI: 0.124-25.463, P=0.016), amniotic fluid contamination (OR 3.223, 95% CI: 1.049-9.901, P=0.041), low 1-minute Apgar score (≤3) (OR 92.425, 95% CI: 15.522-550.343, P<0.001), and low 5-minute Apgar score (≤7) (OR 12.641, 95% CI: 2.894-55.227, P=0.001) may increase risk of HIE. In addition, amniotic fluid contamination, low 1-minute Apgar score (≤3), and low 5-minute Apgar score (≤7) may increase risk of HIE among newborns born to women without previous childbearing history, but not in newborns born to women with previous childbearing history.

Conclusion

Low birth weight (<2.5 kg), amniotic fluid contamination, low 1-minute Apgar score (≤3), and 5-minute Apgar score (≤7) may increase risk of HIE.

Clinical Characteristics and Risk Factors of Neonatal Hypoxic-Ischaemic Encephalopathy and Its Associated Neurodevelopmental Outcomes During the First Two Years of Life: A Retrospective Study in Saudi Arabia

Objective

This study aimed to determine the clinical characteristics and factors associated with neonatal hypoxic-ischaemic encephalopathy (HIE) and its neurodevelopmental outcomes.

Methods

We conducted retrospective case-control research to investigate the clinical and labour-related risk factors for HIE. In addition, a single-centre cohort study was conducted on infants with HIE to describe their neurodevelopment from birth to 24 months. For this investigation, cases with a diagnosis of HIE who were born at King Abdullah Children's Specialist Hospital (KASCH), Riyadh, Saudi Arabia, between 2015 and 2019 were identified and matched with controls from the same facility (1:4). Each case's clinical information was extracted using electronic medical records. In addition, 24-month follow-up HIE cases were included in a cohort study to describe their neurodevelopmental outcomes.

Results

The sample includes 60 infants diagnosed with HIE and 234 infants serving as controls, with a mean gestational age of 38.8 weeks (SD 1.6) and a predominance of males (56.4%). Around one-third of the HIE cases (36.6%) had moderate HIE (stage 2), whereas 35.1% of infants had severe HIE (stage 3), according to Sarnat staging. Compared to the control group, children with HIE were twice as likely to be born to mothers with maternal comorbidities and more likely to have prepartum and intrapartum complications. A 24-month follow-up of neurodevelopmental outcomes for HIE babies revealed that approximately 24% exhibited delays in gross motor skill development, 22% in fine motor skill development, 33% in language skill development, and 22% in social skill development.

Conclusion

In the HIE group, maternal comorbidities and prepartum or intrapartum complications were more common. The severity grade of HIE can be used to predict neurodevelopmental consequences. Enhancing patient care and rehabilitation requires a minimum of 24 months of neurodevelopmental follow-up.

The influence of late prematurity on the encephalopathy exam of infants with neonatal encephalopathy

BACKGROUND

Late preterm (LPT) infants are increasingly treated for hypoxic-ischemic encephalopathy (HIE). However, neurodevelopmental differences of LPT infants may independently influence the neurologic exam and confound care.

METHODS

Perinatal and outcome characteristics were extracted along with the worst autonomic and state/neuromuscular/reflex Sarnat components in a cross-section of infants with moderate/severe HIE. Infants were classified as late preterm (LPT, 34-36 weeks) or term (>36 weeks).

RESULTS

250 infants were identified, 55 were late preterm. LPT infants had lower mean gestational age and birthweight and greater length of stay (LOS). LPT infants had higher median scores for the Moro and respiratory autonomic components, but no difference in total score.

CONCLUSIONS

LPT infants had increased LOS, worse Moro reflex, and respiratory status, but no clinically or statistically significant differences in total Sarnat scores. Although it is important to note the impact of immaturity on the exam, it is unlikely to independently alter management.

Necroptosis Blockade Potentiates the Neuroprotective Effect of Hypothermia in Neonatal Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy (NE) caused by hypoxia-ischemia (HI) affects around 1 per 1000 term newborns and is the leading cause of acquired brain injury and neurodisability. Despite the use of hypothermia (HT) as a standard of care, the incidence of NE and its devastating outcomes remains a major issue. Ongoing research surrounding add-on neuroprotective strategies against NE is important as HT effects are limited, leaving 50% of treated patients with neurological sequelae. Little is known about the interaction between necroptotic blockade and HT in neonatal HI. Using a preclinical Lewis rat model of term human NE induced by HI, we showed a neuroprotective effect of Necrostatin-1 (Nec-1: a compound blocking necroptosis) in combination with HT. The beneficial effect of Nec-1 added to HT against NE injuries was observed at the mechanistic level on both pMLKL and TNF-α, and at the anatomical level on brain volume loss visualized by magnetic resonance imaging (MRI). HT alone showed no effect on activated necroptotic effectors and did not preserve the brain MRI volume. This study opens new avenues of research to understand better the specific cell death mechanisms of brain injuries as well as the potential use of new therapeutics targeting the necroptosis pathway.

Risk factors for hypoxic-ischemic encephalopathy in cases of severe acidosis: A case-control study

INTRODUCTION

The aim of the study was to identify the obstetric risk factors for hypoxic-ischemic encephalopathy (HIE) in infants with asphyxia at birth.

MATERIAL AND METHODS

This multicenter case-control study covered the 5-year period from 2014 through 2018 and included newborns ≥36 weeks of gestation with an umbilical pH at birth ≤7.0. Cases were newborns who developed moderate or severe HIE; they were matched with controls with pH ≤7.0 at birth over the same period without moderate or severe HIE. The factors studied were maternal, gestational, intrapartum, delivery-related, and neonatal characteristics. A multivariable analysis was performed to study the maternal, obstetric, and neonatal factors independently associated with moderate or severe HIE.

RESULTS

Our review of the records identified 41 cases and 98 controls. Compared with controls, children with moderate or severe HIE had a lower 5-min Apgar score, lower umbilical artery pH, and higher cord lactate levels at birth and at 1 h of life. Obstetric factors associated with moderate or severe HIE were the occurrence of an acute event (adjusted odds ratio [aOR] 6.4; 95% confidence interval [CI] 1.8-22.5), maternal fever (aOR 3.5; 95% CI 1.0-11.9), and thick meconium during labor (aOR 2.9; 95% CI 1.0-8.6).

CONCLUSIONS

HIE is associated with a lower 5-min Apgar score and with the severity of acidosis at birth and at 1 h of life. In newborns with a pH <7.0 at birth, the occurrence of an acute obstetric event, maternal fever, and thick meconium are independent factors associated with moderate or severe HIE.

Placental findings are not associated with neurodevelopmental outcome in neonates with hypoxic-ischemic encephalopathy - an 11-year single-center experience

OBJECTIVES

Although neonates with moderate to severe hypoxic ischemic encephalopathy (HIE) receive therapeutic hypothermia (TH), 40-50% die or have significant neurological disability. The aim of this study is to analyse the association of placental pathology and neurodevelopmental outcome in cooled neonates with HIE at 18-24 months of age.

METHODS

Retrospective analysis of prospectively collected data on 120 neonates registered in the Swiss National Asphyxia and Cooling Register born between 2007 and 2017. This descriptive study examines the frequency and range of pathologic findings in placentas of neonates with HIE. Placenta pathology was available of 69/120 neonates, whose results are summarized as placental findings. As neonates with HIE staged Sarnat score 1 (21/69) did not routinely undergo follow-up assessments and of six neonates staged Sarnat Score 2/3 no follow-up assessments were available, 42/48 (88%) neonates remain to assess the association between placental findings and outcome.

RESULTS

Of the 42/48 (88%) neonates with available follow up 29% (12/42) neonates died. Major placenta abnormalities occurred in 48% (20/42). Major placenta abnormality was neither associated with outcome at 18-24 months of age (OR 1.75 [95% CI 0.50-6.36, p=0.381]), nor with death by 2 years of age (OR 1.96 [95% CI 0.53-7.78, p=0.320]).

CONCLUSIONS

In this study cohort there could not be shown an association between the placenta findings and the neurodevelopmental outcome at 18-24 months of age.

Temporal Characterization of Microglia-Associated Pro- and Anti-Inflammatory Genes in a Neonatal Inflammation-Sensitized Hypoxic-Ischemic Brain Injury Model

Hypoxic-ischemic encephalopathy (HIE) mainly affects preterm and term newborns, leading to a high risk of brain damage. Coexisting infection/inflammation and birth asphyxia are key factors associated with intracerebral increase of proinflammatory cytokines linked to HIE. Microglia are key mediators of inflammation during perinatal brain injury, characterized by their phenotypic plasticity, which may facilitate their participation in both the progression and resolution of injury-induced inflammation. The purpose of this study was to investigate the temporal expression of genes associated with pro- and anti-inflammatory cytokines as well as the nucleotide-binding domain, leucine-rich repeat protein (NLRP-3) inflammasome from microglia cells. For this purpose, we used our established neonatal rat model of inflammation-sensitized hypoxic-ischemic (HI) brain injury in seven-day-old rats. We assessed gene expression profiles of 11 cytokines and for NLRP-3 using real-time PCR from sorted CD11b/c microglia of brain samples at different time points (3.5 h after LPS injection and 0, 5, 24, 48, and 72 hours post HI) following different treatments: vehicle, E. coli lipopolysaccharide (LPS), vehicle/HI, and LPS/HI. Our results showed that microglia are early key mediators of the inflammatory response and exacerbate the inflammatory response following HI, polarizing into a predominant proinflammatory M1 phenotype in the early hours post HI. The brains only exposed to HI showed a delay in the expression of proinflammatory cytokines. We also demonstrated that NLRP-3 plays a role in the inflammatory resolution with a high expression after HI insult. The combination of both, a preinfection/inflammation condition and hypoxia-ischemia, resulted in a higher proinflammatory cytokine storm, highlighting the significant contribution of acute inflammation sensitizing prior to a hypoxic insult on the severity of perinatal brain damage.

Risk factors for neonatal encephalopathy in late preterm and term singleton births in a large California birth cohort

OBJECTIVE

The objective was to investigate maternal and pregnancy characteristics associated with neonatal encephalopathy (NE).

STUDY DESIGN

We queried an administrative birth cohort from California between 2011 and 2017 to determine the association between each factor and NE with and without hypothermia treatment.

RESULTS

From 3 million infants born at 35 or more weeks of gestation, 6,857 cases of NE were identified (2.3 per 1000 births), 888 (13%) received therapeutic hypothermia. Risk factors for NE were stronger among cases receiving hypothermia therapy. Substance-related diagnosis, preexisting diabetes, preeclampsia, and any maternal infection were associated with a two-fold increase in risk. Maternal overweight/obesity, nulliparity, advanced maternal age, depression, gestational diabetes or hypertension, and short or long gestations also predicted NE. Young maternal age, Asian race and Hispanic ethnicity, and cannabis-related diagnosis lowered risk of NE.

CONCLUSIONS

By disseminating these results, we encourage further interrogation of these perinatal factors.

Utilization of Therapeutic Hypothermia and Neurological Injury in Neonates with Mild Hypoxic-Ischemic Encephalopathy: A Report from Children's Hospital Neonatal Consortium

OBJECTIVE

This study was aimed to describe utilization of therapeutic hypothermia (TH) in neonates presenting with mild hypoxic-ischemic encephalopathy (HIE) and associated neurological injury on magnetic resonance imaging (MRI) scans in these infants.

STUDY DESIGN

Neonates ≥ 36 weeks' gestation with mild HIE and available MRI scans were identified. Mild HIE status was assigned to hyper alert infants with an exaggerated response to arousal and mild HIE as the highest grade of encephalopathy recorded. MRI scans were dichotomized as "injury" versus "no injury."

RESULTS

A total of 94.5% (257/272) neonates with mild HIE, referred for evaluation, received TH. MRI injury occurred in 38.2% (104/272) neonates and affected predominantly the white matter (49.0%, n = 51). Injury to the deep nuclear gray matter was identified in (10.1%) 20 infants, and to the cortex in 13.4% (n = 14 infants). In regression analyses (odds ratio [OR]; 95% confidence interval [CI]), history of fetal distress (OR = 0.52; 95% CI: 0.28-0.99) and delivery by caesarian section (OR = 0.54; 95% CI: 0.31-0.92) were associated with lower odds, whereas medical comorbidities during and after cooling were associated with higher odds of brain injury (OR = 2.31; 95% CI: 1.37-3.89).

CONCLUSION

Majority of neonates with mild HIE referred for evaluation are being treated with TH. Odds of neurological injury are over two-fold higher in those with comorbidities during and after cooling. Brain injury predominantly involved the white matter.

KEY POINTS

· Increasingly, neonates with mild HIE are being referred for consideration for hypothermia therapy.. · Drift in clinical practice shows growing number of neonates treated with hypothermia as having mild HIE.. · MRI data show that 38% of neonates with mild HIE have brain injury, predominantly in the white matter..

The Relationship between Nuchal Cord and Adverse Obstetric and Neonatal Outcomes: Retrospective Cohort Study

Objective: The twisting of the umbilical cord around the fetal neck is a common phenomenon in the delivery room, and despite the lack of univocal evidence of its negative impact on perinatal events, it causes anxiety and stress in patients. The aim of the study was to assess the prevalence of nuchal cord and its impact on adverse obstetric and neonatal outcomes. Methods: We conducted a retrospective cohort study. All patients who gave birth in the clinic within one year (n = 1467) were included in the study group. We compared the prevalence of nuchal cord in distinct subgroups of patients. In the next stage, we estimated the chance of specific perinatal outcomes and compared the neonatal outcomes between groups with and without nuchal cord. Results: Nuchal cord was present in 24% of labors. It was twice as common among patients giving birth vaginally (32.14%) than among patients giving birth by a caesarean section (16.78%, p < 0.001). Nuchal cord was also more frequent in births with meconium-stained amniotic fluid (33.88% vs. 23.34%, p = 0.009). In the group of patients with nuchal cord, we observed a slight increase in the risk of a non-reassuring fetal heart rate trace (OR = 1.55, CI 95% 1.02−2.36) as an indication of the completion of labor by caesarean delivery. We did not note an increase in the risk of completing natural childbirth by vacuum extraction. In the group of nuchal cord patients, there was a higher chance of a serious or moderate neonatal condition in the first minute of life (Apgar 0−7 points) (OR = 2.00, 95% CI = 1.14−3.49). Conclusions: Nuchal cord increases the risk of a caesarean delivery due to a non-reassuring fetal heart rate trace. Nuchal cord increases the chance of a reduced Apgar score (0−7 points) in the first minute of life. The observed relationships do not translate to neonatal arterial blood gas testing.

Outcomes of infants with hypoxic-ischemic encephalopathy during COVID-19 pandemic lockdown in Canada: a cohort study

PURPOSE

To evaluate change in the severity of hypoxic-ischemic encephalopathy (HIE) and associated morbidities between pre- and during COVID-19 pandemic periods in Canada.

METHODS

We conducted a retrospective cohort study extracting the data from level-3 NICUs participating in Canadian Neonatal Network (CNN). The primary outcome was a composite of death in the first week after birth and/or stage 3 HIE (Sarnat and Sarnat). Secondary outcomes included rate and severity of HIE among admitted neonates, overall mortality, brain injury on magnetic resonance imaging (MRI), neonates requiring resuscitation, organ dysfunction, and therapeutic hypothermia (TH) usage. We included 1591 neonates with gestational age ≥ 36 weeks with HIE during the specified periods: pandemic cohort from April 1st to December 31st of 2020; pre-pandemic cohort between April 1st and December 31st of 2017, 2018, and 2019. We calculated the odds ratio (OR) and confidence intervals (CI).

RESULTS

We observed no significant difference in the primary outcome (15% vs. 16%; OR 1.08; 95%CI 0.78-1.48), mortality in the first week after birth (6% vs. 6%; OR 1.10, 95%CI 0.69-1.75), neonates requiring resuscitation, organ dysfunction, TH usage, or rate of brain injury. In the ad hoc analysis, per 1000 live births, there was an increase in the rate of infants with HIE and TH use.

CONCLUSIONS

Severity of HIE, associated morbidities, and mortality were not significantly different during the pandemic lockdown compared to a pre-pandemic period in Canada. Anticipated risks and difficulties in accessing healthcare have not increased the mortality and morbidities in neonates with HIE in Canada.

Learning the impact of acute and chronic diseases on forecasting neonatal encephalopathy

OBJECTIVE

There is a wide range of risk factors predisposing to the onset of neonatal encephalopathy (NE), including maternal antepartum/intrapartum comorbidities or events. However, few studies have investigated the difference in the impact of acute and chronic diseases on forecasting NE, which could assist clinicians in choosing the best course of action to prevent NE or reduce its severity and complications. In this study, we aimed to engineer features based on acute and chronic diseases and assess the differences of the impact of acute and chronic diseases on NE prediction using machine learning models.

MATERIALS AND METHODS

We used ten years of electronic health records of mothers from a large academic medical center to develop three types of features: chronic disease, recurrence of an acute disease, and temporal relationships between acute diseases. Two types of NE prediction models, based on acute and chronic diseases, respectively, were trained with feature selection. We further compared the prediction performance of the models with two state-of-the-art NE forecasting models. The machine learning models ranked the three types of engineered features based on their contributions to the NE prediction.

RESULTS

The NE model trained on acute disease features showed significantly higher AUC than the model relying on chronic disease features (AUC difference: 0.161, p-value < 0.001). The NE model trained on both acute and chronic disease features achieved the highest average AUC (0.889), with a significant improvement over the best existing model (0.854) with p = 0.0129. Recurrence of "known or suspected fetal abnormality affecting management of mother (655)" was assigned the highest weights in predicting NE.

CONCLUSIONS

Machine learning models based on the three types of engineered features significantly improve NE prediction. Our results specifically suggest that acute disease-associated features play a more important role in predicting NE.

Effect of intra-partum Oxytocin on neonatal encephalopathy: a systematic review and meta-analysis

Background

Oxytocin is widely used for induction and augmentation of labour, particularly in low- and middle-income countries (LMICs). In this systematic review and meta-analysis, we examined the effect of intra-partum Oxytocin use on neonatal encephalopathy.

Methods

The protocol for this study was registered with PROSPERO (ID: CRD42020165049). We searched Medline, Embase and Web of Science Core Collection databases for papers published between January 1970 and May 2021. We considered all studies involving term and near-term (≥36 weeks’ gestation) primigravidae and multiparous women. We included all randomised, quasi-randomised clinical trials, retrospective studies and non-randomised prospective studies reporting intra-partum Oxytocin administration for induction and/or augmentation of labour. Our primary outcome was neonatal encephalopathy. Risk of bias was assessed in non-randomised studies using the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool. The RoB 2.0 tool was used for randomised studies. A Mantel-Haenszel statistical method and random effects analysis model were used for meta-analysis. Odds ratios were used to determine effect measure and reported with 95% confidence intervals.

Results

We included data from seven studies (6 Case-control studies, 1 cluster-randomised trial) of which 3 took place in high-income countries (HICs) and 4 in LMICs. The pooled data included a total of 24,208 women giving birth at or after 36 weeks; 7642 had intra-partum Oxytocin for induction and/or augmentation of labour, and 16,566 did not receive intra-partum Oxytocin. Oxytocin use was associated with an increased prevalence of neonatal encephalopathy (Odds Ratio 2.19, 95% CI 1.58 to 3.04; p < 0.00001).

Conclusions

Intra-partum Oxytocin may increase the risk of neonatal encephalopathy. Future clinical trials of uterotonics should include neonatal encephalopathy as a key outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04216-3.

Medico-legal considerations in the context of neonatal encephalopathy and therapeutic hypothermia

Neonatal encephalopathy (NE) is a significant complication of the peripartum period. It can lead to lifelong neurologic disabilities, including cerebral palsy, cognitive impairments, developmental delays, and epilepsy. Induced hypothermia is the first therapy, which has shown promise in improving the outcomes for neonates with moderate to severe NE following a presumed intrapartum insult. NE is also a frequent source of medical malpractice litigation. In this paper, we will review salient features of the American Tort System as it pertains to medical malpractice. We will discuss the obstetric medico-legal implications of therapeutic hypothermia and suggest a five-step approach to analyzing neonatal cases for causation, etiology, timing of occurrence, responsibility, and liability. We will close with three illustrative clinical cases.

Acute and Chronic Placental Abnormalities in a Multicenter Cohort of Newborn Infants with Hypoxic-Ischemic Encephalopathy

OBJECTIVE

To examine the frequency of placental abnormalities in a multicenter cohort of newborn infants with hypoxic-ischemic encephalopathy (HIE) and to determine the association between acuity of placental abnormalities and clinical characteristics of HIE.

STUDY DESIGN

Infants born at ≥36 weeks of gestation (n = 500) with moderate or severe HIE were enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy Trial. A placental pathologist blinded to clinical information reviewed clinical pathology reports to determine the presence of acute and chronic placental abnormalities using a standard classification system.

RESULTS

Complete placental pathologic examination was available for 321 of 500 (64%) trial participants. Placental abnormalities were identified in 273 of 321 (85%) and were more common in infants ≥40 weeks of gestation (93% vs 81%, P = .01). A combination of acute and chronic placental abnormalities (43%) was more common than either acute (20%) or chronic (21%) abnormalities alone. Acute abnormalities included meconium staining of the placenta (41%) and histologic chorioamnionitis (39%). Chronic abnormalities included maternal vascular malperfusion (25%), villitis of unknown etiology (8%), and fetal vascular malperfusion (6%). Infants with chronic placental abnormalities exhibited a greater mean base deficit at birth (-15.9 vs -14.3, P = .049) than those without such abnormalities. Patients with HIE and acute placental lesions had older mean gestational ages (39.1 vs 38.0, P < .001) and greater rates of clinically diagnosed chorioamnionitis (25% vs 2%, P < .001) than those without acute abnormalities.

CONCLUSIONS

Combined acute and chronic placental abnormalities were common in this cohort of infants with HIE, underscoring the complex causal pathways of HIE.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02811263.

Cytokine and chemokine responses to injury and treatment in a nonhuman primate model of hypoxic-ischemic encephalopathy treated with hypothermia and erythropoietin

Predicting long-term outcome in infants with hypoxic-ischemic encephalopathy (HIE) remains an ongoing clinical challenge. We investigated plasma biomarkers and their association with 6-month outcomes in a nonhuman primate model of HIE with or without therapeutic hypothermia (TH) and erythropoietin (Epo). Twenty-nine Macaca nemestrina were randomized to control cesarean section (n = 7) or 20 min of umbilical cord occlusion (UCO, n = 22) with either no treatment (n = 11) or TH/Epo (n = 11). Initial injury severity was scored using 30-min arterial pH, base deficit, and 10-min Apgar score. Twenty-four plasma cytokines, chemokines, and growth factors were measured 3, 6, 24, 72, and 96 h after UCO. Interleukin 17 (IL-17) and macrophage-derived chemokine (MDC) differentiated the normal/mild from moderate/severe injury groups. Treatment with TH/Epo was associated with increased monocyte chemotactic protein-4 (MCP-4) at 3 h-6h, and significantly lower MCP-4 and MDC at 24 h-72h, respectively. IL-12p40 was lower at 24 h-72h in animals with death/cerebral palsy (CP) compared to survivors without CP. Baseline injury severity was the single best predictor of death/CP, and predictions did not improve with the addition of biomarker data. Circulating chemokines associated with the peripheral monocyte cell lineage are associated with severity of injury and response to therapy, but do not improve ability to predict outcomes.

Perinatal Risk Factors Influencing Neonatal Hypoxic Ischemic Encephalopathy in Southern China: A Case-Control Study

OBJECTIVE

In this study, our objective was to explore the relevant influencing factors of neonatal hypoxic-ischemic encephalopathy (HIE) in Southern China and provide scientific basis for improving the quality of life for neonates.

STUDY DESIGN

A retrospective analysis of 306 cases with HIE neonates who were admitted during April 2015 to October 2017 was conducted. A total of 306 non-HIE patients admitted to the same hospital during the same period were also included as controls. The basic clinical characteristics were analyzed, and the risk factors for HIE were assessed by logistic regression analysis.

RESULTS

Univariate analysis showed that the differences in medicals during pregnancy, placenta previa, fetal distress during labor, cesarean section, amniotic fluid contamination, abnormal labor stage, and Apgar showed significantly different in the case group and the control group (p < 0.05). The multivariate logistic regression analysis revealed that the placenta previa, medicals during pregnancy, fetal distress, abnormal labor stage, Apgar's score, amniotic fluid contamination, and cesarean section were independent risk factors for HIE.

CONCLUSION

The placenta previa, medicals during pregnancy, fetal distress, and abnormal labor stage can increase the risk of HIE. Early detection, early diagnosis, and treatment might make great achievement in improving the life quality of HIE neonates.

Transplanted Oligodendrocyte Progenitor Cells Survive in the Brain of a Rat Neonatal White Matter Injury Model but Less Mature in Comparison with the Normal Brain

Preterm infants have a high risk of neonatal white matter injury (WMI) caused by hypoxia-ischemia. Cell-based therapies are promising strategies for neonatal WMI by providing trophic substances and replacing lost cells. Using a rat model of neonatal WMI in which oligodendrocyte progenitors (OPCs) are predominantly damaged, we investigated whether insulin-like growth factor 2 (IGF2) has trophic effects on OPCs in vitro and whether OPC transplantation has potential as a cell replacement therapy. Enhanced expression of Igf2 mRNA was first confirmed in the brain of P5 model rats by real-time polymerase chain reaction. Immunostaining for IGF2 and its receptor IGF2 R revealed that both proteins were co-expressed in OLIG2-positive and GFAP-positive cells in the corpus callosum (CC), indicating autocrine and paracrine effects of IGF2. To investigate the in vitro effect of IGF2 on OPCs, IGF2 (100 ng/ml) was added to the differentiation medium containing ciliary neurotrophic factor (10 ng/ml) and triiodothyronine (20 ng/ml), and IGF2 promoted the differentiation of OPCs into mature oligodendrocytes. We next transplanted rat-derived OPCs that express green fluorescent protein into the CC of neonatal WMI model rats without immunosuppression and investigated the survival of grafted cells for 8 weeks. Although many OPCs survived for at least 8 weeks, the number of mature oligodendrocytes was unexpectedly small in the CC of the model compared with that in the sham-operated control. These findings suggest that the mechanism in the brain that inhibits differentiation should be solved in cell replacement therapy for neonatal WMI as same as trophic support from IGF2.

Fetal ECG signal processing and identification of hypoxic pregnancy conditions in-utero

The fetal heart rate (fHR) variability and fetal electrocardiogram (fECG) are considered the most important sources of information about fetal wellbeing. Non-invasive fetal monitoring and analysis of fECG are paramount for clinical trials. They enable examining the fetal health status and detecting the heart rate changes associated with insufficient oxygenation to cut the likelihood of hypoxic fetal injury. Despite the fact that significant advances have been achieved in electrocardiography and adult ECG signal processing, the analysis of fECG is still in its infancy. Due to accurate fetal morphology extraction techniques have not been properly developed, many areas require particular attention on the way of fully understanding the changes in variability in the fetus and implementation of the non-invasive techniques suitable for remote home care which is increasingly in demand for high-risk pregnancy monitoring. In this paper, we introduce an integrated approach for fECG signal extraction and processing based on various methods for fetal welfare investigation and hypoxia risk estimation. To the best of our knowledge, this is the first attempt to introduce the auto-generated risk scoring in fECG to achieve early warning on fetus' safety and provide the physician with additional information about the possible fetal complications. The proposed method includes the following stages: fECG extraction, fHR and fetal heart rate variability (fHRV) calculation, hypoxia index (HI) evaluation and risk estimation. The extracted signals were examined by assessing Signal to Noise Ratio (SNR) and mean square error (MSE) values. The results obtained demonstrated great potential, but more profound research and validation, as well as a consistent clinical study, are needed before implementation into the hospital and at-home monitoring.

Brief hypoxia in late gestation sheep causes prolonged disruption of fetal electrographic, breathing behaviours and can result in early labour

KEY POINTS

Brief episodes of severe fetal hypoxia can arise in late gestation as a result of interruption of normal umbilical blood flow Systemic parameters and blood chemistry indicate complete recovery within 1-2 hours, although the long-term effects on fetal brain functions are unknown Fetal sheep were subjected to umbilical cord occlusion (UCO) for 10 min at 131 days of gestation, and then monitored intensively until onset of labour or delivery (<145 days of gestation) Normal patterns of fetal behaviour, including breathing movements, episodes of high and low voltage electorcortical activity, eye movements and postural (neck) muscle activity, were disrupted for 3-10 days after the UCO Preterm labour and delivery occurred in a significant number of the pregnancies after UCO compared to the control (sham-UCO) cohort.

ABSTRACT

Complications arising from antepartum events such as impaired umbilical blood flow can cause significant fetal hypoxia. These complications can be unpredictable, as well as difficult to detect, and thus we lack a detailed understanding of the (patho)physiological changes that occur between the antenatal in utero event and birth. In the present study, we assessed the consequences of brief (∼10 min) umbilical cord occlusion (UCO) in fetal sheep at ∼0.88 gestation on fetal plasma cortisol concentrations and fetal behaviour [electrocortical (EcoG), electo-oculargram (EOG), nuchal muscle electromyography (EMG) and breathing activities] in the days following UCO. UCO caused a rapid onset of fetal hypoxaemia, hypercapnia, and acidosis; however, by 6 h, all blood parameters and cardiovascular status were normalized and not different from the control (Sham-UCO) cohort. Subsequently, the incidence of fetal breathing movements decreased compared to the control group, and abnormal behavioural patterns developed over the days following UCO and leading up to the onset of labour, which included increased high voltage and sub-low voltage ECoG and EOG activities, as well as decreased nuchal EMG activity. Fetuses subjected to UCO went into labour 7.9 ± 3.6 days post-UCO (139.5 ± 3.2 days of gestation) compared to the control group fetuses at 13.6 ± 3.3 days post-sham UCO (144 ± 2.2 days of gestation; P < 0.05), despite comparable increases in fetal plasma cortisol and a similar body weight at birth. Thus, a single transient episode of complete UCO late in gestation in fetal sheep can result in prolonged effects on fetal brain activity and premature labour, suggesting persisting effects on fetal cerebral metabolism.

Impact of neonatal anoxia and hypothermic treatment on development and memory of rats

Therapeutic hypothermia (TH) is well established as a standard treatment for term and near-term infants. However, therapeutic effects of hypothermia following neonatal anoxia in very premature babies remains inconclusive. The present rodent model of preterm neonatal anoxia has been shown to alter developmental milestones and hippocampal neurogenesis, and to disrupt spatial learning and memory in adulthood. These effects seem to be reduced by post-insult hypothermia. Epigenetic-related mechanisms have been postulated as valuable tools for developing new therapies. Dentate gyrus neurogenesis is regulated by epigenetic factors. This study evaluated whether TH effects in a rodent model of preterm oxygen deprivation are based on epigenetic alterations. The effects of TH on both developmental features (somatic growth, maturation of physical characteristics and early neurological reflexes) and performance of behavioral tasks at adulthood (spatial reference and working memory, and fear conditioning) were investigated in association with the possible involvement of the epigenetic operator Enhancer of zeste homolog 2 (Ezh2), possibly related to long-lasting effects on hippocampal neurogenesis. Results showed that TH reduced both anoxia-induced hippocampal neurodegeneration and anoxia-induced impairments on risk assessment behavior, acquisition of spatial memory, and extinction of auditory and contextual fear conditioning. In contrast, TH did not prevent developmental alterations caused by neonatal anoxia and did not restore hippocampal neurogenesis or cause changes in EZH2 levels. In conclusion, despite the beneficial effects of TH in hippocampal neurodegeneration and in reversing disruption of performance of behavioral tasks following oxygen deprivation in prematurity, these effects seem not related to developmental alterations and hippocampal neurogenesis and, apparently, is not caused by Ezh2-mediated epigenetic alteration.

Neonatal Encephalopathy: Beyond Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy is a clinical syndrome of neurologic dysfunction that encompasses a broad spectrum of symptoms and severity, from mild irritability and feeding difficulties to coma and seizures. It is vital for providers to understand that the term "neonatal encephalopathy" is simply a description of the neonate's neurologic status that is agnostic to the underlying etiology. Unfortunately, hypoxic-ischemic encephalopathy (HIE) has become common vernacular to describe any neonate with encephalopathy, but this can be misleading. The term should not be used unless there is evidence of perinatal asphyxia as the primary cause of encephalopathy. HIE is a common cause of neonatal encephalopathy; the differential diagnosis also includes conditions with infectious, vascular, epileptic, genetic/congenital, metabolic, and toxic causes. Because neonatal encephalopathy is estimated to affect 2 to 6 per 1,000 term births, of which HIE accounts for approximately 1.5 per 1,000 term births, (1)(2)(3)(4)(5)(6) neonatologists and child neurologists should familiarize themselves with the evaluation, diagnosis, and treatment of the diverse causes of neonatal encephalopathy. This review begins by discussing HIE, but also helps practitioners extend the differential to consider the broad array of other causes of neonatal encephalopathy, emphasizing the epidemiology, neurologic presentations, diagnostics, imaging findings, and therapeutic strategies for each potential category.

Placental origins of neonatal diseases: toward a precision medicine approach

The placenta is the single most reliable source for precise information on intrauterine environment, as well as maternal and fetal health. It mediates the physiology of two distinct yet highly interconnected individuals. The pathology that develops in the placenta, and the adaptations the placenta undergoes to mitigate this pathology, may influence the later life health of the mother and baby. Pathological placental examination provides a unique opportunity to explore and understand the intrauterine environment, as well as providing a record of events that may be associated with adverse pregnancy outcomes. A number of placental lesions have been described in association with various neonatal morbidities. The purpose of this review is to summarize the evidence for the association of placental pathologic lesions with neurodevelopmental outcomes infants with specific neonatal morbidities, including (1) neonatal encephalopathy, (2) bronchopulmonary dysplasia, (3) congenital heart diseases, and (4) autism spectrum disorders. For each of these disease processes, we will also propose specific research priorities in future studies. We conclude with a hospital-specific protocol for triaging which placentas should receive histological evaluation as a fundamental first step for the field of neuroplacentology to guide precision-based therapeutic approaches in the affected newborns. IMPACT: The purpose of this review is to summarize the evidence for placental origins of neonatal diseases. We propose specific research priorities in the field of neuroplacentology in future studies. We also present a targeted hospital-based approach for triaging which placentas should receive histological evaluation.

Surviving and Thriving: Early Intervention for Neonatal Survivors With Developmental Disability in Uganda

Global attention on early child development, inclusive of those with disability, has the potential to translate into improved action for the millions of children with developmental disability living in low- and middle-income countries. Nurturing care is crucial for all children, arguably even more so for children with developmental disability. A high proportion of survivors of neonatal conditions such as prematurity and neonatal encephalopathy are affected by early child developmental disability. The first thousand days of life is a critical period for neuroplasticity and an important window of opportunity for interventions, which maximize developmental potential and other outcomes. Since 2010, our group has been examining predictors, outcomes, and experiences of neonatal encephalopathy in Uganda. The need for an early child intervention program to maximize participation and improve the quality of life for children and families became apparent. In response, the "ABAaNA early intervention program," (now re-branding as 'Baby Ubuntu') a group participatory early intervention program for young children with developmental disability and their families, was developed and piloted. Piloting has provided early evidence of feasibility, acceptability, and impact and a feasibility trial is underway. Future research aims to develop programmatic capacity across diverse settings and evaluate its impact at scale.

Perinatal hypoxic-ischemic damage: review of the current treatment possibilities

Neonatal hypoxic-ischemic encephalopathy is a disorder with heterogeneous manifestation due to asphyxia during perinatal period. It affects approximately 3-12 children per 1000 live births and cause death of 1 million neonates worldwide per year. Besides, motor disabilities, seizures, impaired muscle tone and epilepsy are few of the consequences of hypoxic-ischemic encephalopathy. Despite an extensive research effort regarding various treatment strategies, therapeutic hypothermia with intensive care unit supportive treatment remains the only approved method for neonates who have suffered from moderate to severe hypoxic-ischemic encephalopathy. However, these protocols are only partially effective given that many infants still suffer from severe brain damage. Thus, further research to systematically test promising neuroprotective treatments in combination with hypothermia is essential. In this review, we discussed the pathophysiology of hypoxic-ischemic encephalopathy and delved into different promising treatment modalities, such as melatonin and erythropoietin. However, preclinical studies and clinical trials are still needed to further elucidate the mechanisms of action of these modalities.

Study on serum Tau protein level and neurodevelopmental outcome of placental abruption with neonatal hypoxic-ischemic encephalopathy

Objective: The aim of this study was to explore differences in serum Tau protein levels and neurodevelopmental prognoses of placental abruption or umbilical cord around neck with hypoxic-ischemic encephalopathy (HIE).Methods: Forty neonates with moderate/severe HIE divided into placental abruption with HIE group (placental abruption with hypoxic-ischemic encephalopathy (PA-HIE) group) (n = 18) and umbilical cord around the neck with HIE group (umbilical cord around the neck with hypoxic-ischemic encephalopathy (UCAN-HIE) group) (n = 22). Healthy term newborns comprised the control group (n = 35). Serum Tau protein levels were measured using an enzyme-linked immunosorbent assay 24 hours (3.50 hours [1.00-24.00]) after birth. Neurodevelopment outcomes were assessed based on the Gesell Developmental Scale at 9 months of age.Results: Serum Tau protein levels were significantly higher in 40 cases (1013 pg/ml [538.04-1190.42]) than in the control group (106.41 pg/ml [64.55-154.71], p = .0001). Serum Tau protein levels in the PA-HIE group (1024.46 pg/ml [657.88-1190.42]) were significantly higher than those in the UCAN-HIE group (892.78 pg/ml [538.04-1179.50], p = .0149). The development quotient score in the PA-HIE group (67.0 [47.0-90.0]) was significantly lower than that in the UCAN-HIE group (81.5 [52.6-100.0]) (p = .0028). The component ratio of neurodevelopmental retardation in the PA-HIE group (44.45%) was significantly higher than that in the UCAN-HIE group (22.73%) (X² = 13.3138, p = .0013).Conclusions: Compared with the UCAN-HIE group, the serum Tau protein level and the component ratio of neurodevelopmental retardation were significantly higher in the PA-HIE group.

Association of traction force and adverse neonatal outcome in vacuum-assisted vaginal delivery: A prospective cohort study

INTRODUCTION

Traction force is a possible risk factor for adverse neonatal outcome in vacuum extraction delivery, but the knowledge is scarce and further investigation is needed. Our hypothesis was that high-level traction force increases the risk of admission to the neonatal intensive care unit.

MATERIAL AND METHODS

The study was a hospital-based prospective cohort study on low- and mid-vacuum extractions at the labor and delivery ward, Karolinska University Hospital, Huddinge, Sweden. Traction forces were measured in 331 women. An electronical handle was used to measure and register traction force. The main exposure variable was high-level traction force (≥75th percentile) during the first three pulls and the primary outcome was admission to the neonatal intensive care unit. Logistic regression was used to estimate the adjusted risk.

RESULTS

Among the exposed, 14/84 (16.7%) were admitted to neonatal intensive care, and among the unexposed 10/247 (4%). The crude odds ratio (OR) of admission to the neonatal intensive care unit when exposed to high-level traction force was 4.7, and the adjusted (birthweight, gestational length, cup detachment, number of pulls, duration, duration >15 minutes, mid-cavity fetal head station, failed extraction, indication and parity) OR was 2.85 (95% confidence interval [CI] 1.09-7.48). No significant effect was seen in Apgar scores <7 at 5 minutes or pH <7.1.

CONCLUSIONS

High-level traction force may be a risk factor for neonatal complications. Although these results do not mandate any alterations in clinical guidelines, perioperative feedback on traction force may be useful to alert the obstetrician to a timely conversion to cesarean section. To study plausible traction force specific outcomes such as head traumas, a larger sample size is required.

Variability and sex-dependence of hypothermic neuroprotection in a rat model of neonatal hypoxic-ischaemic brain injury: a single laboratory meta-analysis

Therapeutic hypothermia (HT) is standard care for term infants with hypoxic–ischaemic (HI) encephalopathy. However, the efficacy of HT in preclinical models, such as the Vannucci model of unilateral HI in the newborn rat, is often greater than that reported from clinical trials. Here, we report a meta-analysis of data from every experiment in a single laboratory, including pilot data, examining the effect of HT in the Vannucci model. Across 21 experiments using 106 litters, median (95% CI) hemispheric area loss was 50.1% (46.0–51.9%; n = 305) in the normothermia group, and 41.3% (35.1–44.9%; n = 317) in the HT group, with a bimodal injury distribution. Median neuroprotection by HT was 17.6% (6.8–28.3%), including in severe injury, but was highly-variable across experiments. Neuroprotection was significant in females (p < 0.001), with a non-significant benefit in males (p = 0.07). Animals representing the median injury in each group within each litter (n = 277, 44.5%) were also analysed using formal neuropathology, which showed neuroprotection by HT throughout the brain, particularly in females. Our results suggest an inherent variability and sex-dependence of the neuroprotective response to HT, with the majority of studies in the Vannucci model vastly underpowered to detect true treatment effects due to the distribution of injury.

Incidence, Intrapartum Risk Factors, and Prognosis of Neonatal Hypoxic-Ischemic Encephalopathy Among Infants Born at 35 Weeks Gestation or More

INTRODUCTION

Neonatal hypoxic-ischemic encephalopathy (HIE) is associated with neonatal mortality, acute neurological injury, and long-term neurodevelopmental disabilities; however, the association between intrapartum factors and HIE remains unclear.

METHODS

This population-based cohort study used linked obstetrical and newborn data derived from the Nova Scotia Atlee Perinatal Database (NSAPD, 1988-2015) and the AC Allen Perinatal Follow-Up Program Database (2006-2015) for all pregnancies with live, non-anomalous newborns ≥35 weeks gestation, not delivered by pre-labour cesarean section. Temporal trends in HIE incidence were described, and logistic regression estimated odds ratios (OR) with 95% confidence intervals (CI) for the association of intrapartum factors with HIE.

RESULTS

The NSAPD identified 227 HIE cases in the population of 226 711 deliveries from 1988 to 2015. Women with clinical chorioamnionitis in labour (OR 8.0; 95% CI 3.9-16), emergency cesarean delivery (OR 10; 95% CI 7.6-14), shoulder dystocia (OR 3.5; 95% CI 2.1-5.7), placental abruption (OR 18; 95% CI 11-29), and cord prolapse (OR 30; 95% CI 15-61) were more likely to have newborns with HIE. Two-thirds of newborns with HIE had an abnormal intrapartum fetal heart rate tracing. The mortality rate among infants with HIE was 27% by 3 years of age. Neurodevelopmental outcomes in the surviving infants were normal in 43% and showed severe developmental delay in 40%.

CONCLUSION

Overall, the rate of HIE was low in infants born at ≥35 weeks gestation. The identification of associated intrapartum factors should promote increased surveillance in these clinical situations and emphasize the importance of careful management to optimize newborn outcomes.

Methylene Blue Prevents Retinal Damage Caused by Perinatal Asphyxia in the Rat

Perinatal asphyxia (PA) is responsible for a large proportion of neonatal deaths and numerous neurological sequelae, including visual dysfunction and blindness. In PA, the retina is exposed to ischemia/reoxygenation, which results in nitric oxide (NO) overproduction and neurotoxicity. We hypothesized that methylene blue (MB), a guanylyl cyclase inhibitor, and free-radical scavenger currently used in the clinic, may block this pathway and prevent PA-induced retinal degeneration. Male rat pups were subjected to an experimental model of PA. Four groups were studied: normally delivered (CTL), normally delivered treated with 2 mg Kg-1 MB (MB), exposed to PA for 20 min at 37°C (PA), and exposed to PA and, then, treated with MB (PA-MB). Scotopic electroretinography performed 45 days after birth showed that PA animals had significant defects in the a- and b-waves and oscillatory potentials (OP). The same animals presented a significant increase in the thickness of the inner retina and a large number of TUNEL-positive cells. All these physiological and morphological parameters were significantly prevented by the treatment with MB. Gene expression analysis demonstrated significant increases in iNOS, MMP9, and VEGF in the eyes of PA animals, which were prevented by MB treatment. In conclusion, MB regulates key players of inflammation, matrix remodeling, gliosis, and angiogenesis in the eye and could be used as a treatment to prevent the deleterious visual consequences of PA. Given its safety profile and low cost, MB may be used clinically in places where alternative treatments may be unavailable.

Placental pathology and neonatal brain MRI in a randomized trial of erythropoietin for hypoxic-ischemic encephalopathy

BACKGROUND

Newborns with hypoxic-ischemic encephalopathy (HIE) may exhibit abnormalities on placental histology. In this phase II clinical trial ancillary study, we hypothesized that placental abnormalities correlate with MRI brain injury and with response to treatment.

METHODS

Fifty newborns with moderate/severe encephalopathy who received hypothermia were enrolled in a double-blind, placebo-controlled trial of erythropoietin for HIE. A study pathologist reviewed all available clinical pathology reports to determine the presence of chronic abnormalities and acute chorioamnionitis. Neonatal brain MRIs were scored using a validated HIE scoring system.

RESULTS

Placental abnormalities in 19 of the 35 (54%) patients with available pathology reports included chronic changes (N = 13), acute chorioamnionitis (N = 9), or both (N = 3). MRI subcortical brain injury was less common in infants with a placental abnormality (26 vs. 69%, P = 0.02). Erythropoietin treatment was associated with a lower global brain injury score (median 2.0 vs. 11.5, P = 0.003) and lower rate of subcortical brain injury (33 vs. 90%, P = 0.01) among patients with no chronic placental abnormality but not in patients whose placentas harbored a chronic abnormality.

CONCLUSION

Erythropoietin treatment was associated with less brain injury only in patients whose placentas exhibited no chronic histologic changes. Placentas may provide clues to treatment response in HIE.

Therapeutic hypothermia for hypoxic-ischemic encephalopathy after perinatal sentinel events: less brain injury on MRI and improved neurodevelopmental outcome at 18-36 months

OBJECTIVE

To study the association between perinatal sentinel events (PSE) and brain MRI/neurodevelopmental outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) receiving therapeutic hypothermia (TH).

DESIGN

This is a retrospective single-center study. Data collection included perinatal history, brain MRI, and neurodevelopmental outcome.

RESULTS

Out of the 182 neonates, 53 (29%) neonates had PSE and 129 (71%) neonates did not have PSE. Neonates with PSE had more normal MRIs (76%) compared with neonates without PSE (55%), p = 0.01. PSE was associated with favorable motor (p = 0.02), language outcome (p = 0.03), and trend to better cognitive scores (p = 0.13). In PSE, favorable motor outcome persisted (OR for impairment 0.15 (0.003-0.84), p = 0.03) after adjusting for the degree of encephalopathy and brain MRI injury. Injury on brain MRI despite TH after PSE was associated with unfavorable neurodevelopmental outcome (p < 0.001).

CONCLUSION

Neonates with HIE receiving TH after PSE had less severe injury on brain MRI after rewarming, and improved motor and language outcomes at 18-36 months.

Benefits of hypothermia in neonatal arterial ischemic strokes: A preclinical study

BACKGROUND

There is currently no targeted treatment available for neonatal arterial ischemic strokes (NAIS). Epidemiological studies demonstrated that perinatal infection/inflammation, peripartum hypoxia, and occlusion of the internal carotid tree are the main determinants of NAIS. The well-established benefit of therapeutic hypothermia (HT) in neonatal encephalopathy due to diffuse hypoxia-ischemia provides a rationale for the potential use of HT as a neuroprotective strategy in NAIS.

METHODS

We used a rat model to reproduce the most prevalent human physiopathological scenario of NAIS. The neuroprotective effect of HT was measured by morphometric magnetic resonance imaging, [¹⁸ F] fluorodeoxyglucose (FDG) metabolic activity by positron emission tomography/computed tomography, and behavioral tests.

RESULTS

HT (a) prevented the occurrence of 44% of NAIS, (b) reduced the volume of strokes by 37%, (c) enhanced [¹⁸ F] FDG metabolic activity within the territory of the occluded carotid artery, and (d) improved motor behavior. Both morphometric and metabolic techniques showed consistently that HT provided a neuroprotective effect located in the motor cortex, hippocampus, and caudate-putamen.

CONCLUSION

Through combining anatomical, metabolic imaging, and behavioral studies, our study provides evidence of neuroprotective effects of HT in NAIS. These results are potentially translational to human NAIS.

Antimicrobial therapy utilization in neonates with hypoxic-ischemic encephalopathy (HIE): a report from the Children's Hospital Neonatal Database (CHND)

OBJECTIVE(S)

Quantify antimicrobial therapy (AMT) use in newborns with hypoxic-ischemic encephalopathy treated with therapeutic hypothermia (HIE/TH).

STUDY DESIGN

Newborns with HIE/TH were identified from the Children's Hospital Neonatal Database (CHND). Early infection (onset ≤7 days of life) was defined as "confirmed" (culture proven) or "suspected infection" (culture negative but treated) and compared with a "no infection" group.

RESULTS

1501/1534 (97.8%) neonates received AMT. 36 (2.3%) had confirmed, 255 (16.6%) suspected, and 1243 (81.0%) had no infection. The median (IQR) AMT duration was 13 (8-21), 8 (7-10), and 3 (3-7) days for the three groups, respectively (p < 0.001). AMT duration of use varied significantly across centers, adjusted for covariates (OR 1.88, 95% CI: 1.43-2.46).

CONCLUSION(S)

Incidence of early confirmed infection in neonates with HIE/TH (23/1000) is significantly higher than reported rates of early onset sepsis in term and near term infants (0.5-1.0/1000 live births). Antimicrobial-stewardship opportunities exist in infants with negative cultures.

Antenatal and intrapartum risk factors for neonatal hypoxic ischemic encephalopathy

OBJECTIVE

To identify antenatal and intrapartum risk factors for neonatal hypoxic ischemic encephalopathy (HIE).

STUDY DESIGN

A single center, retrospective cohort study was conducted for 25,494 singleton births ≥36 weeks' gestation born between 2009 and 2016. Univariate and multivariate analyses were performed to identify risk factors for HIE.

RESULTS

Thirty-seven infants met HIE inclusion criteria. Independent antenatal risk factors included primigravida, previous fetal death/stillbirth, antidepressant use, illicit drug use, Rh sensitization, and adjusted gestational weight gain >13.6 kg. Independent intrapartum risk factors identified were placental abruption, ruptured uterus, moderate-to-heavy meconium stained amniotic fluid, and delivery by cesarean-section. An intrapartum risk factor was present in 70.3% of the HIE group compared with 29.6% of the non-HIE group.

CONCLUSION

Intrapartum period risk factors appear to be important for the development of HIE. Gestational weight gain may serve as an important modifiable factor to reduce the risk of HIE.

Oropharyngeal Dysphagia in Breastfeeding Neonates with Hypoxic-Ischemic Encephalopathy on Therapeutic Hypothermia

Purpose: To identify symptoms of oropharyngeal dysphagia (OPD) in breastfeeding neonates with hypoxic-ischemic encephalopathy (HIE) on therapeutic hypothermia (TH). Early identification of feeding problems in neonates with HIE by speech-language therapists (SLTs) may prevent secondary complications of OPD such as aspiration pneumonia and death. Materials and Methods: Twenty-eight full-term neonates with HIE (mean chronological age = 4.5 days) and 30 healthy term controls were prospectively recruited for this case-control study. Participants with HIE (mild [n = 15], moderate [n = 11], severe [n = 2]), diagnosed by pediatricians, received whole-body TH. Feeding was clinically evaluated by an SLT using the Preterm Infant Breastfeeding Behavior Scale. Results: Twenty-five neonates (89.2%) had at least one symptom of OPD. Falling asleep during feeding, noticeable oral secretions, coughing, and flaring nostrils were symptoms of OPD most frequently identified. The HIE group displayed limited arousal during breastfeeding and had less obvious rooting, shallower latching onto the breast, and more single sucks in comparison to term newborns. The HIE group had significantly more closed eyes and minimal movement during breastfeeding, while controls showed the quiet-alert state ideal for breastfeeding. Conclusions: OPD was identified in the majority of infants with HIE. Underlying the appearance of an inactive neonate with HIE may be OPD that could be overlooked if not investigated. Interprofessional collaboration between SLTs, pediatricians and nurses to determine feeding-readiness is imperative. SLTs may assist in decision-making to improve safety of breastfeeding in this population. This study contributes to the small body of research on early breastfeeding of neonates with HIE.

Maternal hypertensive disorders in pregnancy and risk of hypoxic-ischemia encephalopathy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is one of the most serious birth complications for neonates. Few studies reported the relationship between maternal blood pressure disorders and risk of neonatal HIE.

OBJECTIVE

This study was conducted to examine whether maternal hypertensive disorders in pregnancy increase the risk of HIE.

METHODS

The analyses were performed using data from a large population-based cohort study aiming to prevent neural tube defects by supplementation with folic acid. The subjects comprised 183,981 women with singleton live births delivered at gestational ages of 32-42 weeks, who registered in two southern provinces in China. Blood pressure was measured by trained health care workers at each prenatal visit. Diagnosis information on HIE was recorded at the time of delivery.

RESULTS

Totally 19,298 women (10.49%) were diagnosed with maternal hypertensive disorders in pregnancy and 255 infants (1.4 per 1000) with HIE, respectively. Compared with the normotensive group, a great increment in the risk of HIE was observed in women with hypertensive disorders (adjusted RR = 2.40, 95% confidence interval [CI]: 1.79-3.22) after adjusting for maternal confounding factors. A greater association was presented among preterm (32-36 weeks) infants with an adjusted RR of 5.45 (95% CI: 2.79, 10.65) compared to a RR of 2.09 (95% CI: 1.49, 2.92) among full-term (37-42 weeks) infants (p for heterogeneity < .05). Further stratification analyses showed that no matter with or without small for gestational age (SGA), maternal hypertensive disorders were associated with the increased risk for HIE. Sensitivity analyses excluding infants with low or high birth weight did not appreciably change the findings.

CONCLUSIONS

Our present study demonstrated a positive association of maternal hypertensive disorders in pregnancy with the risk of neonatal HIE.