Long-Term Neurologic Consequences following Fetal Growth Restriction: The Impact on Brain Reserve.

BACKGROUND: Fetal growth restriction (FGR) corresponds to the fetus's inability to achieve an adequate weight gain based on genetic potential and gestational age. It is an important cause of morbidity and mortality. SUMMARY: In this review, we address the challenges of diagnosis and classification of FGR. We review how chronic fetal hypoxia impacts brain development. We describe recent advances on placental and fetal brain imaging using magnetic resonance imaging and how they offer new noninvasive means to study growth restriction in humans. We go on to review the impact of FGR on brain integrity in the neonatal period, later childhood, and adulthood and review available therapies. KEY MESSAGES: FGR consequences are not limited to the perinatal period. We hypothesize that impaired brain reserve, as defined by structure and size, may predict some concerning epidemiological data of impaired cognitive outcomes and dementia with aging in this group of patients.

Falls in oxygen saturations accompany electrographic seizures in term neonates: an observational study.

BACKGROUND: Effective seizure detection is important however, clinical signs of seizure activity may be subtle in neonates. This study aimed to systematically investigate SpO2 and respiratory pattern changes associated with EEG seizures in term-born neonates. METHOD: An observational study in term neonates at risk of seizures admitted to a single tertiary level neonatal intensive care unit. Synchronised high-resolution physiological data (ECG, pulse oximetry, respiration) and EEG/amplitude-integrated EEG (aEEG) monitoring were recorded. Sections of traces with evidence of clear EEG seizure activity were compared with physiological data recorded at the same time. RESULTS: 22/44 (50%) neonates who had aEEG monitoring were noted to have electrographic seizures. Physiologic download measurements were available for 11 of these neonates. In nine of these, an acute drop in oxygen saturation (SpO2) of at least 5% was noted in at least one seizure. Accompanying apnoeas were noted in three neonates. CONCLUSION: Acute decreases in SpO2 were seen in term neonates associated with seizures and these were not always accompanied by an apnoeic episode. Physiologic download in association with EEG monitoring may assist in improving seizure detection. Unexplained drops in SpO2 could indicate further investigation for possible seizures in at-risk neonates. IMPACT: A decrease in blood oxygen saturation (SpO2) associated with EEG seizures can occur in term infants with HIE or perinatal stroke. Drops in SpO2 associated with EEG seizures in term infants with HIE or stroke may occur in the absence of apnoeas. Unexplained acute falls in SpO2 in sick neonates may suggest possible seizures. Drops in SpO2 associated with seizures in term infants can occur over less than 3 minutes. Physiological monitoring alongside EEG monitoring could help to improve seizure detection.

Variation between Clinician-Recorded and Downloaded Invasive Blood Pressure in Extremely Preterm Infants.

OBJECTIVE: This study aimed to examine the variation between clinician-recorded and continuously downloaded invasive blood pressure (BP). STUDY DESIGN: Prospective study where invasive BP data were downloaded every 10 seconds for the first week of life. Hourly clinician-recorded BP was recorded. Agreement between the two methods were examined. RESULTS: A total of 1,180 BP measurements were examined from 42 preterm infants with a mean (standard deviation [SD]) gestation and birthweight of 25.7 weeks (1.4) and 802 g (177) respectively. The mean (SD) bias was -0.11 mm Hg (3.17), but the 95% limits of agreement (LOA) varied between -6.3 and +6.1 mm Hg. Inotrope usage was significantly higher for BP measurements that fell in the 5% outliers when compared with those that fell within the 95% LOA (62.7 vs. 44.6%, p = 0.006). CONCLUSION: Clinicians showed no systematic bias to over- or underrecord BP, but some of the greatest differences were found in infants receiving inotropes. KEY POINTS: · BP is a commonly recorded cardiovascular parameter in the neonatal intensive care unit.. · Invasively measured BP remains the gold standard.. · Clinician-recorded BP showed no systematic bias in over-or underrecording invasive BP..

Association between Multi-Organ Involvement and Brain Injury in Cooled Newborns: A Statistical Approach.

INTRODUCTION: In the event of fetal hypoxia-ischemia, circulation to the brain and central organs is thought to be preserved. The objective of the study was to explore the relationship between the presence of brain injury on MRI and multi-organ involvement, as reflected in routinely collected laboratory (lab) values in babies who have undergone therapeutic hypothermia (TH) after hypoxic-ischemic encephalopathy (HIE). METHODS: Peak and trough values, and age at peak/trough, were obtained for 10 lab markers collected for clinical care, representing hematopoiesis, coagulation, inflammation, hepatic, and renal function, from 71 consecutively recruited newborns from four tertiary neonatal centers undergoing TH. Cerebral MR images obtained as part of clinical care were assessed by two raters with expertise, in a blinded fashion. RESULTS: There was no significant association between the presence of cerebral injury on MRI and systems involvement in newborns who have undergone TH. However, the peak/trough platelet ratio was significantly associated with cerebral injury. Also, the peak platelet, lymphocyte, and urea counts occurred significantly later in babies with substantial brain injury compared to those without. CONCLUSION: Using a statistical approach, we demonstrate that there is no clear relationship between multi-organ involvement and cerebral injury in babies with HIE who have undergone TH. We infer that babies may have cerebral injury in the absence of involvement of other organ systems. The platelet count ratio as an independent biomarker of cerebral injury in this group requires further investigation. Reference ranges of lab values for term newborns undergoing TH are provided.

Alterations in the Stool Microbiome in Newborns Undergoing Mild Therapeutic Hypothermia after Hypoxic-Ischemic Encephalopathy.

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is associated with brain injury in newborns and may lead to disability or death. Mild therapeutic hypothermia (TH) is an effective neuroprotective intervention and an established standard of care in western countries. The gut microbiome, the genomic and physicochemical contribution of the gut microbiota, serves important functions and is increasingly recognized as a major influencer on development. The impact of HIE and TH on the evolving gut microbiota of the newborn remains to be elucidated. OBJECTIVE: The objective of this study was to carry out an exploratory study on the effects of HIE and TH on the gut microbiome in term neonates. METHODS AND RESULTS: Stool samples were obtained from 28 newborns with HIE (median age 68 h) undergoing TH on the neonatal unit (HIE TH group), with a follow-on stool sample available for 20 of these babies (median age 151 h). For comparison, a single stool specimen was obtained from 19 healthy newborns on the postnatal ward (median age 34 h). The microbiota composition was determined using established microbial DNA extraction and 16S rRNA gene sequencing methodology. There was no difference in the mode of delivery or the method of feeding the newborns, once established, between the 2 groups. All the infants in the HIE TH group had received antibiotics compared to only one of the controls. A lower α-diversity, quantified by the Shannon diversity index, was noted in the microbiota of the HIE TH group in comparison to the control group. The HIE TH group had a higher mean relative abundance (MRA) of facultative anaerobes and aerobes such as Staphylococcus species and a lower MRA of strict anaerobes, such as members of the Bacteroides genus, compared to the control. Also, there was a significant reduction in the MRA of the genus Bifidobacterium in the HIE TH group. Although the mode of delivery exerts a profound influence on the gut microbiota of the newborn, distance-based redundancy analysis showed that TH may exert an independent influence. This study could not determine the independent contribution of the use of antibiotics or the neonatal intensive care unit environment. CONCLUSION: In this study, we demonstrate an alteration in the microbiota composition in newborns undergoing TH for HIE.

Neonatal Seizure Management: Is the Timing of Treatment Critical?

OBJECTIVE: To assess the impact of the time to treatment of the first electrographic seizure on subsequent seizure burden and describe overall seizure management in a large neonatal cohort. STUDY DESIGN: Newborns (36-44 weeks of gestation) requiring electroencephalographic (EEG) monitoring recruited to 2 multicenter European studies were included. Infants who received antiseizure medication exclusively after electrographic seizure onset were grouped based on the time to treatment of the first seizure: antiseizure medication within 1 hour, between 1 and 2 hours, and after 2 hours. Outcomes measured were seizure burden, maximum seizure burden, status epilepticus, number of seizures, and antiseizure medication dose over the first 24 hours after seizure onset. RESULTS: Out of 472 newborns recruited, 154 (32.6%) had confirmed electrographic seizures. Sixty-nine infants received antiseizure medication exclusively after the onset of electrographic seizure, including 21 infants within 1 hour of seizure onset, 15 between 1 and 2 hours after seizure onset, and 33 at >2 hours after seizure onset. Significantly lower seizure burden and fewer seizures were noted in the infants treated with antiseizure medication within 1 hour of seizure onset (P = .029 and .035, respectively). Overall, 258 of 472 infants (54.7%) received antiseizure medication during the study period, of whom 40 without electrographic seizures received treatment exclusively during EEG monitoring and 11 with electrographic seizures received no treatment. CONCLUSIONS: Treatment of neonatal seizures may be time-critical, but more research is needed to confirm this. Improvements in neonatal seizure diagnosis and treatment are also needed.

Common carotid artery blood flow volume in extremely preterm infants.

AIM: The aim of this study was to determine carotid blood flow volume, a surrogate for cerebral blood flow, using Doppler ultrasound in extremely preterm infants. METHODS: In infants <29 weeks, right common carotid artery flow volume (RCCAF) was calculated from vessel diameter and intensity-weighted mean velocity measured using Doppler ultrasound on days 1 and 3. In addition, left ventricular output (LVO), ductus arteriosus characteristics and invasive mean arterial blood pressure (MABP) were obtained. RESULTS: Sixty infants with mean gestation of 25.8 weeks were studied. The median RCCAF increased from 12 (IQR 9-15) mL/kg/min on day 1, to 14 (IQR 12-18) mL/kg/min on day 3 (p = 0.007). RCCAF was positively correlated with invasive MABP on days 1 and 3. RCCAF significantly correlated with LVO in infants with closing or closed ductus arteriosus on day 1. Using multiple regression analysis, RCCAF was significantly associated with invasive MABP on day 1 and to inotropic treatment on day 3. CONCLUSION: Doppler ultrasound can be used to measure RCCAF in extremely preterm infants receiving intensive care. RCCAF increased during the first three days and was positively related to invasive MABP on day 1. Values were lower than previously described in more mature infants. CLINICAL TRIAL REGISTRATION: ISRCTN 83507686.

Early echocardiography does not predict subsequent treatment of symptomatic patent ductus arteriosus in extremely preterm infants.

AIM: To determine whether early echocardiographic ductal parameters identified infants who subsequently received medical or surgical treatment of the patent ductus arteriosus (PDA). METHODS: Infants <29 weeks had PDA size in 2D and colour, flow velocity and patterns obtained on days 1 and 3. Infants were followed up to identify those subsequently receiving treatment for symptomatic PDA by clinicians who were unaware of scan results. Receiver operator characteristics curves and logistic regression were performed. RESULTS: Sixty infants were studied. Mean (SD) gestation and birthweight were 25.8 (1.5) weeks and 817 (190) grams, respectively. Twenty-four (40%) infants received medical treatment, and nine (15%) infants received surgical ligation of PDA at a median age of 12 and 37 days, respectively. PDA size on days 1 and 3, change in ductal size between days 1 and 3, flow pattern/velocity did not predict whether infants subsequently received medical or surgical management of PDA. Using logistic regression, gestation (p = 0.006) was the only factor that predicted whether infants would subsequently receive medical or surgical treatment for PDA in this cohort. CONCLUSION: Echocardiographic ductal parameters on day 1 or 3 did not identify infants who received PDA treatment. Gestation was the most powerful predictor for receiving medical or surgical treatment of PDA.

Hypoxic-Ischaemic Encephalopathy and the Blood-Brain Barrier in Neonates.

This review aims to highlight a possible relationship between hypoxic-ischaemic encephalopathy (HIE) and the disruption of the blood-brain barrier (BBB). Inflammatory reactions perpetuate a large proportion of cerebral injury. The extent of injury noted in HIE is not only determined by the biochemical cascades that trigger the apoptosis-necrosis continuum of cell death in the brain parenchyma, but also by the breaching of the BBB by pro-inflammatory factors. We examine the changes that contribute to the breakdown of the BBB that occur during HIE at a macroscopic, cellular, and molecular level. The BBB is a permeability barrier which separates a large majority of brain areas from the systemic circulation. The concept of a physiological BBB is based at the anatomical level on the neurovascular unit (NVU). The NVU consists of various cellular components that jointly regulate the exchanges that occur at the interface between the systemic circulation and the brain parenchyma. There is increased understanding of the contribution of the components of the NVU, e.g., astrocytes and pericytes, to the maintenance of this physiological barrier. We also explore the development of therapeutic options in HIE, such as harnessing the transport systems in the BBB, to enable the delivery of large molecules with molecular Trojan horse technology, and the reinforcement of the physical barrier with cell-based therapy which utilizes endothelial progenitor cells and stem cells.

A study of microRNAs from dried blood spots in newborns after perinatal asphyxia: a simple and feasible biosampling method.

BACKGROUND: The potential of microRNAs (miRNAs) as bedside biomarkers in selecting newborns with hypoxic-ischemic encephalopathy (HIE) for neuroprotection has yet to be explored. Commonly, blood-based biomarker tests use plasma or serum which don't allow evaluation of both intracellular and extracellular changes. METHODS: We describe a technique to extract and compare expression of miRNAs from a single small 6-mm-diameter dried blood spot (DBS) stored at room temperature with those from EDTA-blood, plasma, and urine. Three miRNAs (RNU6B, let7b, and miR-21) were quantified via extraction and quantitative RT-PCR performed from a DBS and compared with levels from EDTA-blood, plasma, and urine. Secondarily, candidate miRNAs let7b, miR-21, miR-29b, miR-124, and miR-155 in DBS were evaluated as potential biomarkers for HIE. RESULTS: Candidate miRNAs were extractable in all biosamples from newborns, with the highest expression in DBS. There was a good correlation between miRNAs' levels in DBS and EDTA-blood at -80 °C. No significant difference was observed in the miRNA levels between the favorable and unfavorable outcome groups for babies with HIE. CONCLUSION: DBS may be useful for studying the potential of miRNAs as biomarkers for brain injury.

Cerebral function monitoring on a general paediatric ward: feasibility and potential.

UNLABELLED: Cerebral function monitoring is widely used in neonatal intensive care, but its potential role in assessment of older infants is scarcely reported. We reviewed the use of cerebral function monitoring on a general paediatric ward in a series of young infants admitted with abnormal movements. Review of the amplitude-integrated EEG obtained by cerebral function monitoring revealed electrographic seizures in four of seven infants monitored. We also surveyed general paediatric wards in hospitals in our region of the UK to ask about current use of cerebral function monitoring and local availability of formal electroencephalography services. Cerebral function monitoring was not being used in the 16 other paediatric departments surveyed, and there was very limited provision for obtaining a full-array electroencephalogram out-of-hours. CONCLUSION: With adequate training and education, it is feasible to undertake cerebral function monitoring on a general paediatric ward. Continuous cerebral function monitoring is a tool that has potential use for detecting clinical seizures and augmenting clinical neuro-observations of young children admitted to a general paediatric ward. WHAT IS KNOWN: • In intensive care settings, cerebral function monitoring (CFM) has long been used for the continuous bedside monitoring of brain function in critically ill neonates, children and adults. • Very few studies have looked at the use of CFM outside of the intensive care setting, and it is presently unclear if CFM is used in the general paediatric ward. What is new: • CFM is presently not widely used in the general paediatric setting. • With appropriate training and support, CFM can be successfully introduced to the general paediatric ward with the potential to enhance the clinical monitoring of young infants admitted with abnormal movements.

Cerebral maturation on amplitude-integrated electroencephalography and perinatal exposures in preterm infants.

AIM: To determine the associations between perinatal exposures, cerebral maturation on amplitude-integrated encephalography (aEEG) and outcome. METHODS: During this prospective cohort study, 136 infants ≤30 weeks estimated gestational age received 4 h of aEEG at four time points (between the first 2 weeks of life and term-equivalent age) during hospitalisation. Perinatal factors were documented. Associations between perinatal exposures and Burdjalov-scores were investigated. Neurodevelopmental outcome was assessed at the age of two. RESULTS: Immature cyclicity on the initial aEEG recording was associated with higher CRIB score (p = 0.01), vaginal delivery (p = 0.02), male gender (p < 0.01) and death (p = 0.01). Perinatal factors associated with lower Burdjalov-scores included cerebral injury (p < 0.01), sepsis (p < 0.01), lower caffeine dose (p = 0.006), prolonged mechanical ventilation (p = 0.002) and death (p < 0.01). Burdjalov-scores at 30 (ß = 2.62, p < 0.01) and 34 weeks postmenstrual age (ß = 2.89, p = 0.05) predicted motor scores. CONCLUSION: aEEG measures of cyclicity and Burdjalov-scores in the first 6 weeks of life, with an emphasis on 30 and 34 weeks postmenstrual age, demonstrated associations with perinatal factors known to predict adverse neurodevelopmental outcome.

Temporal evolution of electrographic seizures in newborn infants with hypoxic-ischaemic encephalopathy requiring therapeutic hypothermia: a secondary analysis of the ANSeR studies.

BACKGROUND: Despite extensive research on neonatal hypoxic-ischaemic encephalopathy, detailed information about electrographic seizures during active cooling and rewarming of therapeutic hypothermia is sparse. We aimed to describe temporal evolution of seizures and determine whether there is a correlation of seizure evolution with 2-year outcome. METHODS: This secondary analysis included newborn infants recruited from eight European tertiary neonatal intensive care units for two multicentre studies (a randomised controlled trial [NCT02431780] and an observational study [NCT02160171]). Infants were born at 36+0 weeks of gestation with moderate or severe hypoxic-ischaemic encephalopathy and underwent therapeutic hypothermia with prolonged conventional video-electroencephalography (EEG) monitoring for 10 h or longer from the start of rewarming. Seizure burden characteristics were calculated based on electrographic seizures annotations: hourly seizure burden (minutes of seizures within an hour) and total seizure burden (minutes of seizures within the entire recording). We categorised infants into those with electrographic seizures during active cooling only, those with electrographic seizures during cooling and rewarming, and those without seizures. Neurodevelopmental outcomes were determined using the Bayley's Scales of Infant and Toddler Development, Third Edition (BSID-III), the Griffiths Mental Development Scales (GMDS), or neurological assessment. An abnormal outcome was defined as death or neurodisability at 2 years. Neurodisability was defined as a composite score of 85 or less on any subscales for BSID-III, a total score of 87 or less for GMDS, or a diagnosis of cerebral palsy (dyskinetic cerebral palsy, spastic quadriplegia, or mixed motor impairment) or epilepsy. FINDINGS: Of 263 infants recruited between Jan 1, 2011, and Feb 7, 2017, we included 129 infants: 65 had electrographic seizures (43 during active cooling only and 22 during and after active cooling) and 64 had no seizures. Compared with infants with seizures during active cooling only, those with seizures during and after active cooling had a longer seizure period (median 12 h [IQR 3-28] vs 68 h [35-86], p<0·0001), more seizures (median 12 [IQR 5-36] vs 94 [24-134], p<0·0001), and higher total seizure burden (median 69 min [IQR 22-104] vs 167 min [54-275], p=0·0033). Hourly seizure burden peaked at about 20-24 h in both groups, and infants with seizures during and after active cooling had a secondary peak at 85 h of age. When combined, worse EEG background (major abnormalities and inactive background) at 12 h and 24 h were associated with the seizure group: compared with infants with a better EEG background (normal, mild, or moderate abnormalities), infants with a worse EEG background were more likely to have seizures after cooling at 12 h (13 [54%] of 24 vs four [14%] of 28; odds ratio 7·09 [95% CI 1·88-26·77], p=0·0039) and 24 h (14 [56%] of 25 vs seven [18%] of 38; 5·64 [1·81-17·60], p=0·0029). There was a significant relationship between EEG grade at 12 h (four categories) and seizure group (p=0·020). High total seizure burden was associated with increased odds of an abnormal outcome at 2 years of age (odds ratio 1·007 [95% CI 1·000-1·014], p=0·046), with a medium negative correlation between total seizure burden and BSID-III cognitive score (rS=-0·477, p=0·014, n=26). INTERPRETATION: Overall, half of infants with hypoxic-ischaemic encephalopathy had electrographic seizures and a third of those infants had seizures beyond active cooling, with worse outcomes. These results raise the importance of prolonged EEG monitoring of newborn infants with hypoxic-ischaemic encephalopathy not only during active cooling but throughout the rewarming phase and even longer when seizures are detected. FUNDING: Wellcome Trust, Science Foundation Ireland, and the Irish Health Research Board.

Newborns with Favourable Outcomes after Perinatal Asphyxia Have Upregulated Glucose Metabolism-Related Proteins in Plasma.

Hypoxic-ischaemic encephalopathy (HIE) is an important cause of morbidity and mortality globally. Although mild therapeutic hypothermia (TH) may improve outcomes in selected babies, the mechanism of action is not fully understood. A proteomics discovery study was carried out to analyse proteins in the plasma of newborns with HIE. Proteomic analysis of plasma from 22 newborns with moderate-severe HIE that had initially undergone TH, and relative controls including 10 newborns with mild HIE who did not warrant TH and also cord blood from 10 normal births (non-HIE) were carried out using the isobaric Tandem Mass Tag (TMT®) 10plexTM labelling with tandem mass spectrometry. A total of 7818 unique peptides were identified in all TMT10plexTM samples, translating to 3457 peptides representing 405 proteins, after applying stringent filter criteria. Apart from the unique protein signature from normal cord blood, unsupervised analysis revealed several significantly regulated proteins in the TH-treated moderate-severe HIE group. GO annotation and functional clustering revealed various proteins associated with glucose metabolism: the enzymes fructose-bisphosphate aldolase A, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate mutase 1, phosphoglycerate kinase 1, and pyruvate kinase PKM were upregulated in newborns with favourable (sHIE+) outcomes compared to newborns with unfavourable (sHIE-) outcomes. Those with favourable outcomes had normal MR imaging or mild abnormalities not predictive of adverse outcomes. However, in comparison to mild HIE and the sHIE- groups, the sHIE+ group had the additional glucose metabolism-related enzymes upregulated, including triosephosphate isomerase, α-enolase, 6-phosphogluconate dehydrogenase, transaldolase, and mitochondrial glutathione reductase. In conclusion, our plasma proteomic study demonstrates that TH-treated newborns with favourable outcomes have an upregulation in glucose metabolism. These findings may open new avenues for more effective neuroprotective therapy.

Long-chain omega-3 polyunsaturated fatty acids are reduced in neonates with substantial brain injury undergoing therapeutic hypothermia after hypoxic-ischemic encephalopathy.

Hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal morbidity and mortality. Although therapeutic hypothermia is an effective treatment, substantial chronic neurological impairment often persists. The long-chain omega-3 polyunsaturated fatty acids (PUFAs), docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids, offer therapeutic potential in the post-acute phase. To understand how PUFAs are affected by HIE and therapeutic hypothermia we quantified for the first time the effects of HIE and therapeutic hypothermia on blood PUFA levels and lipid peroxidation. In a cross-sectional approach, blood samples from newborns with moderate to severe HIE, who underwent therapeutic hypothermia (sHIE group) were compared to samples from newborns with mild HIE, who did not receive therapeutic hypothermia, and controls. The sHIE group was stratified into cerebral MRI predictive of good (n = 10), or poor outcomes (n = 10; nine developed cerebral palsy). Cell pellets were analyzed for fatty acid content, and plasma for lipid peroxidation products, thiobarbituric acid reactive substances and 4-hydroxy-2-nonenal. Omega-3 Index (% DHA + EPA) was similar between control and HIE groups; however, with therapeutic hypothermia there were significantly lower levels in poor vs. good prognosis sHIE groups. Estimated Δ-6 desaturase activity was significantly lower in sHIE compared to mild HIE and control groups, and linoleic acid significantly increased in the sHIE group with good prognosis. Reduced long-chain omega-3 PUFAs was associated with poor outcome after HIE and therapeutic hypothermia, potentially due to decreased biosynthesis and tissue incorporation. We speculate a potential role for long-chain omega-3 PUFA interventions in addition to existing treatments to improve neurologic outcomes in sHIE.

Physiological CTG categorization in types of hypoxia compared with MRI and neurodevelopmental outcome in infants with HIE.

BACKGROUND: Commonly used methods of CTG classification do not reliably predict neonatal hypoxic-ischemic encephalopathy (HIE). OBJECTIVE: To examine whether a relationship exists between the types of hypoxia as identified on the cardiotocograph using novel physiology-based CTG classification and patterns of injury on neonatal cerebral MRI and later neurodevelopmental outcomes. STUDY DESIGN: A retrospective study of term-born infants admitted to four neonatal units with HIE as part of a brain injury biomarkers study between January 2014 and December 2015. Intrapartum CTG traces were analyzed by two obstetricians trained in physiological CTG classification, blind to neonatal outcomes. Neonatal cerebral MR images were assessed independently by a neuroradiologist and an expert neonatologist. CTG traces were classified into types of hypoxia and allocated to groups; (1) chronic hypoxia or antepartum injury; (2) gradually evolving or subacute hypoxia; and (3) acute hypoxia. RESULTS: Of 106 infants recruited to the study, records were available for 58 cases. Of these, CTGs were available for 37. All 37 had abnormal CTGs. Twenty-four infants, all of whom had received therapeutic hypothermia had cerebral MRI. Fourteen of the 24 (58%) infants had abnormal MRI. In group 1 (chronic hypoxia/antenatal injury), total brain injury was most predominant (4/6 infants). Group 2 (gradually evolving/subacute hypoxia) was associated with peripheral brain injury (5/5 infants). Group 3 (acute hypoxia) was associated with basal-ganglia thalamic injury pattern (3/3 infants). Later neurodevelopmental outcomes were available for 35 cases. Infants suspected to have a pre-labor injury on CTG (group 1) had a higher proportion of adverse neurodevelopmental outcomes (4/10, 40%) compared to groups 2 and 3 (4/25, 16%). CONCLUSION: Using this novel physiology-based CTG classification, we demonstrate an association between types of hypoxia observed on the CTG and MRI patterns of hypoxic brain injury. Infants with CTG trace suggestive of chronic hypoxia or other antenatal injuries were overrepresented in this cohort and were also more likely to have a poor neurodevelopmental outcome.

Lipid Profiles from Dried Blood Spots Reveal Lipidomic Signatures of Newborns Undergoing Mild Therapeutic Hypothermia after Hypoxic-Ischemic Encephalopathy.

Hypoxic-ischemic encephalopathy (HIE) is associated with perinatal brain injury, which may lead to disability or death. As the brain is a lipid-rich organ, various lipid species can be significantly impacted by HIE and these correlate with specific changes to the lipidomic profile in the circulation. Objective: To investigate the peripheral blood lipidomic signature in dried blood spots (DBS) from newborns with HIE. Using univariate analysis, multivariate analysis and sPLS-DA modelling, we show that newborns with moderate-severe HIE (n = 46) who underwent therapeutic hypothermia (TH) displayed a robust peripheral blood lipidomic signature comprising 29 lipid species in four lipid classes; namely phosphatidylcholine (PC), lysophosphatidylcholine (LPC), triglyceride (TG) and sphingomyelin (SM) when compared with newborns with mild HIE (n = 18). In sPLS-DA modelling, the three most discriminant lipid species were TG 50:3, TG 54:5, and PC 36:5. We report a reduction in plasma TG and SM and an increase in plasma PC and LPC species during the course of TH in newborns with moderate-severe HIE, compared to a single specimen from newborns with mild HIE. These findings may guide the research in nutrition-based intervention strategies after HIE in synergy with TH to enhance neuroprotection.

Neuronal let-7b-5p acts through the Hippo-YAP pathway in neonatal encephalopathy.

Despite increasing knowledge on microRNAs, their role in the pathogenesis of neonatal encephalopathy remains to be elucidated. Herein, we identify let-7b-5p as a significant microRNA in neonates with moderate to severe encephalopathy from dried blood spots using next generation sequencing. Validation studies using Reverse Transcription and quantitative Polymerase Chain Reaction on 45 neonates showed that let-7b-5p expression was increased on day 1 in neonates with moderate to severe encephalopathy with unfavourable outcome when compared to those with mild encephalopathy. Mechanistic studies performed on glucose deprived cell cultures and the cerebral cortex of two animal models of perinatal brain injury, namely hypoxic-ischaemic and intrauterine inflammation models confirm that let-7b-5p is associated with the apoptotic Hippo pathway. Significant reduction in neuronal let-7b-5p expression corresponded with activated Hippo pathway, with increased neuronal/nuclear ratio of Yes Associated Protein (YAP) and increased neuronal cleaved caspase-3 expression in both animal models. Similar results were noted for let-7b-5p and YAP expression in glucose-deprived cell cultures. Reduced nuclear YAP with decreased intracellular let-7b-5p correlated with neuronal apoptosis in conditions of metabolic stress. This finding of the Hippo-YAP association with let-7b needs validation in larger cohorts to further our knowledge on let-7b-5p as a biomarker for neonatal encephalopathy.

Electrographic seizures in preterm infants during the first week of life are associated with cerebral injury.

The aim of the study was to determine the incidence of electrographic seizure activity in a prospective cohort of preterm infants and relate it to the presence of cerebral injury. Infants born <30-wk gestation received a median 74 h of continuous 2-channel EEG with amplitude-integrated EEG monitoring in the first week of life. Infants were classified in the abnormal outcome group if they died in the neonatal period and/or had grades 3-4 intraventricular hemorrhage and/or moderate or severe abnormalities on cerebral MRI. Seizures were defined as rhythmic spike and/or wave activity lasting at least 10 s on the raw EEG trace. Eleven of 51 infants monitored had electrographic seizures. These infants were more premature had lower birth weights and a greater proportion had abnormal outcomes. In four infants, seizures preceded ultrasound findings of grades 3-4 intraventricular hemorrhage. Three of the four infants with seizures and concurrent physiologic recordings displayed concurrent rises in heart rate and one showed a fall in respiratory rate. In conclusion, electrographic seizures were more likely to occur in the sicker and more premature infants with abnormal outcomes. Seizures detected on continuous amplitude-integrated EEG monitoring with the raw EEG were associated with poor outcome.