Changing pattern of perinatal brain injury in term infants in recent years

Intraventricular hemorrhage in term infants: a single institutional experience between 2016 and 2020

PURPOSE

Intraventricular hemorrhage (IVH) of prematurity is a known complication of preterm birth. Intraventricular hemorrhage in term infants is much less commonly encountered. To address the lack of information in the current literature concerning this demographic, we offer demographic and image findings that demonstrate etiology and predict the need for permanent cerebrospinal fluid (CSF) diversion.

METHODS

A prospectively maintained database was queried for all patients with intraventricular hemorrhage from 2016 to 2020 treated at our institution. Demographic data and etiology were collected, along with need for and timing of surgical intervention.

RESULTS

A total of 150 IVH patients were identified. Of these patients, 138 were excluded due to prematurity. Twelve patients were born at term with IVH. All patients were followed for at least 8 months. Seven patients (58.3%) underwent ventriculoperitoneal (VP) shunt placement, performed between 4 days and 4 months of age. Superficial siderosis detected by MRI during in-patient stay or follow-up showed a sensitivity of 100% and specificity of 60% for the future development of post-hemorrhagic hydrocephalus (PHH) (p < 0.05). All full-term infants who developed PHH (n = 7, 58.3%) obtained a VP shunt.

CONCLUSION

IVH in term infants occurs infrequently when compared to IVH of prematurity. Etiology of IVH in term infants remains difficult to ascertain, but the majority of patients did demonstrate risk factors. The presence of superficial siderosis on MRI significantly predicted the development of PHH and eventual need for CSF diversion.

Neonatal stroke: Clinical characteristics and neurodevelopmental outcomes

BACKGROUND

Neonatal stroke can potentially result in significant neurological sequelae in affected infants. Studies on neurodevelopmental outcomes and the need for rehabilitation therapies in the first two years are limited. We aimed to describe the clinical characteristics, diagnostic evaluation, and neurodevelopmental outcomes of a cohort of infants with neonatal stroke.

METHODS

A retrospective cohort study of infants with neonatal stroke, from 2011 to 2020. Maternal and infant characteristics were described. Placental pathology, echocardiogram results, and prothrombotic evaluations were reported. The neurodevelopmental outcomes using Bayley scale of infant development (BSID III), rates of epilepsy and cerebral palsy, and the need for rehabilitation therapies at two years were described.

RESULTS

During the study period, 55 infants had neonatal stroke. Majority (93%) were term or late preterm infants. Maternal chorioamnionitis and perinatal HIE were diagnosed in about a third of the infants. Most (66%) of the infants presented with seizures. On brain MRI, the lesions were unilateral in 76% and arterial in origin in 86% of the infants. Meconium exposure (42%), intrauterine inflammation/infection (37%) and fetal vascular malperfusion (16%) were seen on placental histopathology. At two-year BSID III assessment, median (min, max) composite cognitive, language, and motor scores were 100 (55-145), 97 (47-124), and 100 (46-141), respectively. Among this cohort, epilepsy (27%), cerebral palsy (16%) and the need for rehabilitation therapies (physical -24%, occupational -18%, speech -21%) were reported at two years.

CONCLUSION

Neonatal stroke presented commonly in term or late preterm infants with seizures. It was unilateral and arterial in origin in most infants. Maternal chorioamnionitis and perinatal HIE were the most commonly associated conditions at birth. About one-fifth of the infants had mild or severe developmental delays at two years. Epilepsy, cerebral palsy, and need for rehabilitation therapies were noted in a significant proportion of infants at two years.

The Role of the Placenta in Perinatal Stroke: A Systematic Review

CONTEXT

Placental pathology may be an important missing link in the causal pathway of perinatal stroke. The study aim was to systematically review the literature regarding the role of the placenta in perinatal stroke. MEDLINE, Embase, Scopus, and Web of Science electronic databases were searched from 2000 to 2019. Studies were selected based on predefined criteria. To enable comparisons, placental abnormalities were coded using Redline's classification.

RESULTS

Ten studies met the inclusion criteria. Less than a quarter of stroke cases had placental pathology reported. Placental abnormalities were more common among children with perinatal stroke than in the control group. The most frequent placental abnormality was Redline's category 2 (thrombo-inflammatory process).

CONCLUSIONS

Placental abnormalities appear to be associated with perinatal stroke, supporting additional indirect evidence and biological plausibility of a causative role. However, the results should be interpreted cautiously considering the low frequency of placental examination and lack of uniformity in placental pathology reporting.

CLINICAL TRIAL REGISTRATION

PROSPERO Registration no: CRD42017081256.

Outcome Trajectories after Primary Perinatal Hemorrhagic Stroke

BACKGROUND

Perinatal hemorrhagic stroke in late preterm and term neonates is understudied. We describe two-month and two-year neurological outcomes in a prospective cohort.

METHODS

Neonates ≥36 weeks' gestation with spontaneous hemorrhagic stroke (parenchymal and intraventricular) presenting at age ≤28 days were enrolled between March 2007 and May 2015 at three tertiary pediatric centers. Hemorrhagic transformation of arterial ischemic stroke or cerebral sinovenous thrombosis was excluded. The Pediatric Stroke Outcome Measure (PSOM) assessed outcomes. Wilcoxon signed-rank tests evaluated change over time.

RESULTS

Twenty-six neonates were included (median age: 1 day, interquartile range [IQR] 0 to 16; median gestational age: 38.3 weeks, IQR 37.0 to 39.0). Hemorrhage was isolated intraventricular in seven (27%), isolated intraparenchymal in six (23%), and a combination in 10 (39%). Three neonates (12%) died during hospitalization; one died later due to cardiac disease. Among 22 survivors, outcomes were assessed at a median of 2.1 months (IQR 1.7 to 3.3) in 96% and 1.9 years (IQR 1.3 to 2.0) in 73%. Median PSOM scores were 0.0 (IQR 0.0 to 1.0) and 0.25 (IQR 0.0 to 1.3), respectively. At two years, 45% of patients had no or nonimpairing deficits (PSOM <1.0), 30% had mild deficits (PSOM 1.0 to 2.0), and 5% had moderate deficits (PSOM 2.5 to 4.5). Over time, 31% worsened and 6% improved. Although total PSOM scores did not change significantly (P = 0.08), language subscores worsened (P = 0.009). No child developed epilepsy.

CONCLUSIONS

Perinatal hemorrhagic stroke survivors had favorable outcomes in early childhood; at two years moderate to severe deficits occurred in 5%. Language deficits may emerge over time, warranting close follow-up.

Applications of advanced signal processing and machine learning in the neonatal hypoxic-ischemic electroencephalogram

Perinatal hypoxic-ischemic-encephalopathy significantly contributes to neonatal death and life-long disability such as cerebral palsy. Advances in signal processing and machine learning have provided the research community with an opportunity to develop automated real-time identification techniques to detect the signs of hypoxic-ischemic-encephalopathy in larger electroencephalography/amplitude-integrated electroencephalography data sets more easily. This review details the recent achievements, performed by a number of prominent research groups across the world, in the automatic identification and classification of hypoxic-ischemic epileptiform neonatal seizures using advanced signal processing and machine learning techniques. This review also addresses the clinical challenges that current automated techniques face in order to be fully utilized by clinicians, and highlights the importance of upgrading the current clinical bedside sampling frequencies to higher sampling rates in order to provide better hypoxic-ischemic biomarker detection frameworks. Additionally, the article highlights that current clinical automated epileptiform detection strategies for human neonates have been only concerned with seizure detection after the therapeutic latent phase of injury. Whereas recent animal studies have demonstrated that the latent phase of opportunity is critically important for early diagnosis of hypoxic-ischemic-encephalopathy electroencephalography biomarkers and although difficult, detection strategies could utilize biomarkers in the latent phase to also predict the onset of future seizures.

Electroencephalogram studies of hypoxic ischemia in fetal and neonatal animal models

Alongside clinical achievements, experiments conducted on animal models (including primate or non-primate) have been effective in the understanding of various pathophysiological aspects of perinatal hypoxic/ischemic encephalopathy (HIE). Due to the reasonably fair degree of flexibility with experiments, most of the research around HIE in the literature has been largely concerned with the neurodevelopmental outcome or how the frequency and duration of HI seizures could relate to the severity of perinatal brain injury, following HI insult. This survey concentrates on how EEG experimental studies using asphyxiated animal models (in rodents, piglets, sheep and non-human primate monkeys) provide a unique opportunity to examine from the exact time of HI event to help gain insights into HIE where human studies become difficult.

Bedside neurophysiological tests can identify neonates with stroke leading to cerebral palsy

OBJECTIVE

The unspecific symptoms of neonatal stroke still challenge its bedside diagnosis. We studied the accuracy of routine electroencephalography (EEG) and simultaneously recorded somatosensory evoked potentials (EEG-SEP) for diagnosis and outcome prediction of neonatal stroke.

METHODS

We evaluated EEG and EEG-SEPs from a hospital cohort of 174 near-term neonates with suspected seizures or encephalopathy, 32 of whom were diagnosed with acute ischemic or hemorrhagic stroke in MRI. EEG was scored for background activity and seizures. SEPs were classified as present or absent. Developmental outcome of stroke survivors was evaluated from medical records at 8- to 18-months age.

RESULTS

The combination of continuous EEG and uni- or bilaterally absent SEP (n = 10) was exclusively seen in neonates with a middle cerebral artery (MCA) stroke (specificity 100%). Moreover, 80% of the neonates with this finding developed with cerebral palsy. Bilaterally present SEPs did not exclude stroke, but predicted favorable neuromotor outcome in stroke survivors (positive predictive value 95%).

CONCLUSIONS

Absent SEP combined with continuous EEG background in near-term neonates indicates an MCA stroke and a high risk for cerebral palsy.

SIGNIFICANCE

EEG-SEP offers a bedside method for diagnostic screening and a reliable prediction of neuromotor outcome in neonates suspected of having a stroke.

Placental Pathology in Neonatal Stroke: A Retrospective Case-Control Study

OBJECTIVE

To assess the association of placental abnormalities with neonatal stroke.

STUDY DESIGN

This retrospective case-control study at 3 academic medical centers examined placental specimens for 46 children with neonatal arterial or venous ischemic stroke and 99 control children without stroke, using a standard protocol. Between-group comparisons used χ² and Fisher exact t test. Correlations used Spearman correlation coefficient.

RESULTS

Case placentas were more likely than controls to meet criteria for ≥1 of 5 major categories of pathologic abnormality (89% vs 62%; OR, 5.1; 95% CI, 1.9-14.0; P = .0007) and for ≥2 categories (38% vs 8%; OR, 7.3; 95% CI, 2.9-19.0; P < .0001). Fetal vascular malperfusion occurred in 50% of cases and 17% of controls (OR, 4.8; 95% CI, 2.2-10.5; P = .0001). Amniotic fluid inflammation occurred in 46% of cases with arterial ischemic stroke vs 25% of controls (OR, 2.6; 95% CI, 1.1-6.1; P = .037). There was evidence of a "stress response" (meconium plus elevated nucleated red blood cells) in 24% of cases compared with 1% of controls (OR, 31; 95% CI, 3.8-247.0; P < .0001).

CONCLUSIONS

Placental abnormality was more common in children with neonatal stroke compared with controls. All placental findings represent subacute-to-chronic intrauterine stressors. Placental thrombotic processes were associated with both arterial and venous stroke. Our findings provide evidence for specific mechanisms that may predispose to acute perinatal stroke. Amniotic fluid inflammation associated with neonatal arterial ischemic stroke deserves further investigation.

Pathways for Neuroimaging of Neonatal Stroke

PURPOSE

To provide consensus-based, suggested imaging protocols to facilitate the accurate and timely diagnosis of a neonate with symptoms concerning for stroke.

METHODS

The Writing Group, an international collaboration of pediatric neurologists and neuroradiologists with expertise in perinatal and childhood stroke, participated in a series of pediatric stroke neuroimaging symposia. These discussions, in conjunction with extensive literature review, led to a consensus for imaging protocols to guide practitioners in the diagnosis of neonatal stroke subtypes as defined by the National Institute of Neurological Disorders and Stroke Common Data Elements. The epidemiology, clinical presentation, and associated risk factors for arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke are reviewed, with a focused discussion regarding the role of neuroimaging for each subtype.

RESULTS

In a neonate with suspected stroke, magnetic resonance imaging is the preferred modality, given the lack of X-irradiation, superior anatomic resolution, and sensitivity for acute ischemia. Core recommended sequences include diffusion-weighted imaging and apparent diffusion coefficient mapping to diagnose acute ischemia, gradient-recalled echo or susceptibility-weighted imaging to detect intracranial blood and its breakdown products, and T1- and T2-weighted imaging to assess for myelination, extra-axial blood, and edema. Magnetic resonance angiography of the brain may be useful to detect vascular abnormalities, with venography if venous sinus thrombosis is suspected. The application of more novel sequences, as well as the utility of follow up-imaging, is also discussed.

Focal Brain Injury Associated with a Model of Severe Hypoxic-Ischemic Encephalopathy in Nonhuman Primates

Worldwide, hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal mortality and morbidity. To better understand the mechanisms contributing to brain injury and improve outcomes in neonates with HIE, better preclinical animal models that mimic the clinical situation following birth asphyxia in term newborns are needed. In an effort to achieve this goal, we modified our nonhuman primate model of HIE induced by in utero umbilical cord occlusion (UCO) to include postnatal hypoxic episodes, in order to simulate apneic events in human neonates with HIE. We describe a cohort of 4 near-term fetal Macaca nemestrina that underwent 18 min of in utero UCO, followed by cesarean section delivery, resuscitation, and subsequent postnatal mechanical ventilation, with exposure to intermittent daily hypoxia (3 min, 8% O2 3-8 times daily for 3 days). After delivery, all animals demonstrated severe metabolic acidosis (pH 7 ± 0.12; mean ± SD) and low APGAR scores (<5 at 10 min of age). Three of 4 animals had both electrographic and clinical seizures. Serial blood samples were collected and plasma metabolites were determined by 2-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS). The 4 UCO animals and a single nonasphyxiated animal (delivered by cesarean section but without exposure to UCO or prolonged sedation) underwent brain magnetic resonance imaging (MRI) on day 8 of life. Thalamic injury was present on MRI in 3 UCO animals, but not in the control animal. Following necropsy on day 8, brain histopathology revealed neuronal injury/loss and gliosis in portions of the ventrolateral thalamus in all 4 UCO, with 2 animals also demonstrating putamen/globus pallidus involvement. In addition, all 4 UCO animals demonstrated brain stem gliosis, with neuronal loss present in the midbrain, pons, and lateral medulla in 3 of 4 animals. Transmission electron microscopy imaging of the brain tissues was performed, which demonstrated ultrastructural white matter abnormalities, characterized by perinuclear vacuolation and axonal dilation, in 3 of 4 animals. Immunolabeling of Nogo-A, a negative regulator of neuronal growth, was not increased in the injured brains compared to 2 control animals. Using GC × GC-TOFMS, we identified metabolites previously recognized as potential biomarkers of perinatal asphyxia. The basal ganglia-thalamus-brain stem injury produced by UCO is consistent with the deep nuclear/brainstem injury pattern seen in human neonates after severe, abrupt hypoxic-ischemic insults. The UCO model permits timely detection of biomarkers associated with specific patterns of neonatal brain injury, and it may ultimately be useful for validating therapeutic strategies to treat neonatal HIE.

Global Burden, Epidemiologic Trends, and Prevention of Intrapartum-Related Deaths in Low-Resource Settings

Intrapartum-related neonatal deaths include live-born infants who die in the first 28 days of life from neonatal encephalopathy or die before onset of neonatal encephalopathy and have evidence of intrapartum injury. A smaller portion of the population in poorer countries has access to basic obstetric and postnatal care causing neonatal mortality rates to be higher. Presence of a skilled birth attendant and provision of basic emergency obstetric care can reduce intrapartum birth asphyxia by 40%. With the announcement of Sustainable Development Goals and global Every Newborn Action Plan, there is hope that interventions around continuum of care will save lives.

The Stress and Vascular Catastrophes in Newborn Rats: Mechanisms Preceding and Accompanying the Brain Hemorrhages

In this study, we analyzed the time-depended scenario of stress response cascade preceding and accompanying brain hemorrhages in newborn rats using an interdisciplinary approach based on: a morphological analysis of brain tissues, coherent-domain optical technologies for visualization of the cerebral blood flow, monitoring of the cerebral oxygenation and the deformability of red blood cells (RBCs). Using a model of stress-induced brain hemorrhages (sound stress, 120 dB, 370 Hz), we studied changes in neonatal brain 2, 4, 6, 8 h after stress (the pre-hemorrhage, latent period) and 24 h after stress (the post-hemorrhage period). We found that latent period of brain hemorrhages is accompanied by gradual pathological changes in systemic, metabolic, and cellular levels of stress. The incidence of brain hemorrhages is characterized by a progression of these changes and the irreversible cell death in the brain areas involved in higher mental functions. These processes are realized via a time-depended reduction of cerebral venous blood flow and oxygenation that was accompanied by an increase in RBCs deformability. The significant depletion of the molecular layer of the prefrontal cortex and the pyramidal neurons, which are crucial for associative learning and attention, is developed as a consequence of homeostasis imbalance. Thus, stress-induced processes preceding and accompanying brain hemorrhages in neonatal period contribute to serious injuries of the brain blood circulation, cerebral metabolic activity and structural elements of cognitive function. These results are an informative platform for further studies of mechanisms underlying stress-induced brain hemorrhages during the first days of life that will improve the future generation's health.

Fetal Thrombotic Vasculopathy: Perinatal Stroke, Growth Restriction, and Other Sequelae

Clots in the fetal circulation of the placenta may occlude or narrow the lumens of fetal vessels sufficiently to diminish the placental oxygen and nutritional exchange, causing significant reduction in placental function. When extensive, growth restriction, neonatal encephalopathy, and stillbirth may occur. Propagation of clots in other organs, such as brain, kidney, and liver, may affect the function of these organs, resulting in infarcts and neonatal stroke. This article presents an account of the placental pathology and clinical sequelae of this condition, called fetal thrombotic vasculopathy.

The incidence of severe intraventricular hemorrhage based on retrospective analysis of 35939 full-term newborns-report of two cases and review of literature

INTRODUCTION

Intraventricular hemorrhage (IVH) is mostly documented in premature infants, and the younger the gestational age, the more often it occurs. IVH is very rarely reported in full-term neonates.

CASE REPORT

Retrospective analysis was performed in 35939 full-term neonates, who were born in the Clinical Hospital of Gynecology and Obstetrics at the University of Medical Sciences in Poznań. Clinical data were retrieved from their medical records. We report a case series of 2 term newborns, who developed severe IVH grade 3 and 4 with no evidence of asphyxia, neuroinfection, TORCH infections, coagulation disorders and trombocytopenia, metabolic disorders, arteriovenous malformations, and selected genetic abnormalities (factor V Leiden 1601G > A polymorphism and MTHFR 677C > T; 1298A > C polymorphisms). IVH in both cases was complicated by posthemorrhagic hydrocephalus treated with decompressive lumbar punctures and next ventriculoperitoneal shunt placement.

CONCLUSIONS

In conclusion, several factors influence the predisposition for severe IVH in term neonates. Perinatal period complicated by fetal distress, birth trauma, and severe asphyxia should be taken into account. However, it is possible that etiopathogenesis cannot be defined clearly as in our cases. Cranial ultrasounds in a specific group of term newborns (taking into account risk factors for IVH) should be widely recommended.

Optical monitoring of stress-related changes in the brain tissues and vessels associated with hemorrhagic stroke in newborn rats

Stress is a major factor for a risk of cerebrovascular catastrophes. Studying of mechanisms underlying stress-related brain-injures in neonates is crucial for development of strategy to prevent of neonatal stroke. Here, using a model of sound-stress-induced intracranial hemorrhages in newborn rats and optical methods, we found that cerebral veins are more sensitive to the deleterious effect of stress than arteries and microvessels. The development of venous insufficiency with decreased blood outflow from the brain accompanied by hypoxia, reduction of complexity of venous blood flow and high production of beta-arrestin-1 are possible mechanisms responsible for a risk of neonatal hemorrhagic stroke.

Litigation related to intrapartum fetal surveillance

The role of intrapartum care including cardiotocography (CTG) monitoring in cases of perinatal neurological injury receives considerable debate in both clinical and medicolegal settings. The debate, however, has distracted attention from fundamental questions about the timing, mechanism, and preventability of perinatal injury. CTG tracings are used as a surrogate for asphyxia with the timing of intervention ("rescue") predicated on the presumed severity of asphyxia. Using CTG in this way has prevented intrapartum stillbirth, but it has not reduced the long-term injury in part, because, contrary to popular belief, the majority of intrapartum fetal injuries are unassociated with severe hypoxia or severe neonatal depression. This article describes the timing and mechanisms, including mechanical factors, of intrapartum perinatal injury and the benefit of using the CTG, not for the purpose of "rescue", but for identifying risk factors for fetal injury and keeping the fetus out of harm's way.

Sexual dimorphism and brain lateralization impact behavioral and histological outcomes following hypoxia-ischemia in P3 and P7 rats

Neonatal cerebral hypoxia-ischemia (HI) is a major cause of neurological disorders and the most common cause of death and permanent disability worldwide, affecting 1-2/1000 live term births and up to 60% of preterm births. The Levine-Rice is the main experimental HI model; however, critical variables such as the age of animals, sex and hemisphere damaged still receive little attention in experimental design. We here investigated the influence of sex and hemisphere injured on the functional outcomes and tissue damage following early (hypoxia-ischemia performed at postnatal day 3 (HIP3)) and late (hypoxia-ischemia performed at postnatalday 7 (HIP7)) HI injury in rats. Male and female 3- (P3) or 7-day-old (P7) Wistar rats had their right or left common carotid artery occluded and exposed to 8% O2 for 1.5h. Sham animals had their carotids exposed but not occluded nor submitted to the hypoxic atmosphere. Behavioral impairments were assessed in the open field arena, in the Morris water maze and in the inhibitory avoidance task; volumetric extent of tissue damage was assessed using cresyl violet staining at adult age, after completing behavioral assessment. The overall results demonstrate that: (1) HI performed at the two distinct ages cause different behavioral impairments and histological damage in adult rats (2) behavioral deficits following neonatal HIP3 and HIP7 are task-specific and dependent on sex and hemisphere injured (3) HIP7 animals presented the expected motor and cognitive deficits (4) HIP3 animals displayed discrete but significant cognitive impairments in the left hemisphere-injured females (5) HI brain injury and its consequences are determined by animal's sex and the damaged hemisphere, markedly in HIP3-injured animals.

Transcriptomics of the fetal hypothalamic response to brachiocephalic occlusion and estradiol treatment

Estradiol (E2) is a well-known modulator of fetal neuroendocrine activity and has been proposed as a critical endocrine signal readying the fetus for birth and postnatal life. To investigate the modulatory role of E2 on fetal stress responsiveness and the response of the fetal brain to asphyxic stress, we subjected chronically catheterized fetal sheep to a transient (10 min) brachiocephalic artery occlusion (BCO) or sham occlusion. Half of the fetuses received subcutaneous pellets that increased plasma E2 concentrations within the physiological range. Hypothalamic mRNA was analyzed using the Agilent 8x15k ovine array (019921), processed and annotated as previously reported by our laboratory. Analysis of the data by ANOVA revealed that E2 differentially regulated (DR) 561 genes, and BCO DR 894 genes compared with control and E2+BCO DR 1,153 genes compared with BCO alone (all P < 0.05). E2 upregulated epigenetic pathways and downregulated local steroid biosynthesis but did not significantly involve genes known to directly respond to the estrogen receptor. Brachiocephalic occlusion upregulated kinase pathways as well as genes associated with lymphocyte infiltration into the brain and downregulated neuropeptide synthesis. E2 upregulated immune- and apoptosis-related pathways after BCO and reduced kinase and epigenetic pathway responses to the BCO. Responses to BCO are different from responses to hypoxic hypoxia suggesting that mechanisms of responses to these two forms of brain hypoxia are distinct. We conclude that cerebral ischemia caused by BCO might stimulate lymphocyte infiltration into the brain and that this response appears to be modified by estradiol.

Fetal thrombotic vasculopathy is associated with thromboembolic events and adverse perinatal outcome but not with neurologic complications: a retrospective cohort study of 54 cases with a 3-year follow-up of children

OBJECTIVE

to test the hypothesis that placental fetal thrombotic vasculopathy (FTV) is associated with obstetric complications and predisposes the child to unfavorable outcomes.

METHODS

54 placentas with FTV lesions and 100 placentas without FTV lesions were collected over a 5-year period at the Croix-Rousse Pathology Department. Clinical findings including maternal, fetal, neonatal condition and pediatric outcome up to three years were collected for each case and control observation. The statistical analyses were assessed with Wald's chi-square derived from conditional logistic regression modeling.

RESULTS

FTV was associated with a significantly higher frequency of obstetric complications: (pregnancy-induced hypertension (OR 3.620, CI 1.563-8.385), preeclampsia (OR 3.674, CI 1.500-8.998), emergency delivery procedures (OR 3.727, CI 1.477-9.403), cesarean sections (OR 2.684, CI 1.016-7.088)), poor fetal condition (intrauterine growth restriction (IUGR) (OR 5.440, CI 2.007-14.748), nonreassuring fetal heart tracing (OR 6.062, CI 2.280-16.115), difficulties in immediate ex utero adaptation (OR 3.416, CI 1.087-10.732)) and perinatal or early childhood demise (OR 3.043, CI 1.327-6.978). On pathological examination, FTV was associated with marginal cord insertion (OR 3.492, CI 1.350-9.035), cord stricture and hypercoiled cord (OR 3.936, CI 1.209-12.813). Thromboembolic events were significantly more frequent in cases with FTV (OR 2.154, CI 1.032-5.622). Neurological complications within the first 3 years of life were also more frequent in the FTV group compared to the control group, but this association was not statistically significant.

CONCLUSIONS

FTV is associated with maternal complications, pathological findings in the placenta, especially gross cord abnormalities, IUGR, and poor perinatal or early childhood outcome. It may also predispose children to somatic thromboembolic events.

Haemorrhagic stroke in term and late preterm neonates

OBJECTIVE

Few data regarding causes and outcomes of haemorrhagic stroke (HS) in term neonates are available. We characterised risk factors, mechanism and short-term outcomes in term and late preterm neonates with acute HS.

DESIGN

Prospective cohort.

SETTING

Single-centre tertiary care stroke registry.

SUBJECTS

Term and late preterm neonates (≥ 34 weeks gestation), born 2004-2010, with acute HS ≤ 28 days of life were identified, and clinical information was abstracted. Short-term outcomes were assessed via standardised neurological exam and rated using the Paediatric Stroke Outcome Measure (PSOM).

RESULTS

Among 42 neonates, median gestational age was 39.7 weeks (IQR 38-40.7 weeks). Diagnosis occurred at a median of 1 day (IQR 0-7 days) after delivery. Twenty-seven (64%) had intraparenchymal and intraventricular haemorrhage. Mechanism was haemorrhagic transformation of venous or arterial infarction in 22 (53%). Major risk factors included congenital heart disease (CHD), fetal distress and haemostatic abnormalities. Common presentations included seizure, apnoea, and poor feeding or vomiting. Acute hydrocephalus was common. Mortality was 12%. Follow-up occurred in 36/37 survivors at a median of 1 year (IQR 0.5-2.0 years). Among 17/36 survivors evaluated in stroke clinic, 47% demonstrated neurologic deficits. Deficits were mild (PSOM 0.5-1.5) in 9/36 (25%), and moderate-to-severe (PSOM ≥ 2.0) in 8/36 (22%).

CONCLUSIONS

In our cohort with acute HS, most presented with seizures, apnoea and/or poor feeding. Fetal distress and CHD were common. Nearly two-thirds had intraparenchymal with intraventricular haemorrhage. Over half were due to haemorrhagic transformation of infarction. Short-term neurologic deficits were present in 47% of survivors.

Intrapartum-related neonatal encephalopathy incidence and impairment at regional and global levels for 2010 with trends from 1990

BACKGROUND

Intrapartum hypoxic events ("birth asphyxia") may result in stillbirth, neonatal or postneonatal mortality, and impairment. Systematic morbidity estimates for the burden of impairment outcomes are currently limited. Neonatal encephalopathy (NE) following an intrapartum hypoxic event is a strong predictor of long-term impairment.

METHODS

Linear regression modeling was conducted on data identified through systematic reviews to estimate NE incidence and time trends for 184 countries. Meta-analyses were undertaken to estimate the risk of NE by sex of the newborn, neonatal case fatality rate, and impairment risk. A compartmental model estimated postneonatal survivors of NE, depending on access to care, and then the proportion of survivors with impairment. Separate modeling for the Global Burden of Disease 2010 (GBD2010) study estimated disability adjusted life years (DALYs), years of life with disability (YLDs), and years of life lost (YLLs) attributed to intrapartum-related events.

RESULTS

In 2010, 1.15 million babies (uncertainty range: 0.89-1.60 million; 8.5 cases per 1,000 live births) were estimated to have developed NE associated with intrapartum events, with 96% born in low- and middle-income countries, as compared with 1.60 million in 1990 (11.7 cases per 1,000 live births). An estimated 287,000 (181,000-440,000) neonates with NE died in 2010; 233,000 (163,000-342,000) survived with moderate or severe neurodevelopmental impairment; and 181,000 (82,000-319,000) had mild impairment. In GBD2010, intrapartum-related conditions comprised 50.2 million DALYs (2.4% of total) and 6.1 million YLDs.

CONCLUSION

Intrapartum-related conditions are a large global burden, mostly due to high mortality in low-income countries. Universal coverage of obstetric care and neonatal resuscitation would prevent most of these deaths and disabilities. Rates of impairment are highest in middle-income countries where neonatal intensive care was more recently introduced, but quality may be poor. In settings without neonatal intensive care, the impairment rate is low due to high mortality, which is relevant for the scale-up of basic neonatal resuscitation.

Developmental expression of N-methyl-D-aspartate (NMDA) receptor subunits in human white and gray matter: potential mechanism of increased vulnerability in the immature brain

The pathophysiology of perinatal brain injury is multifactorial and involves hypoxia-ischemia (HI) and inflammation. N-methyl-d-aspartate receptors (NMDAR) are present on neurons and glia in immature rodents, and NMDAR antagonists are protective in HI models. To enhance clinical translation of rodent data, we examined protein expression of 6 NMDAR subunits in postmortem human brains without injury from 20 postconceptional weeks through adulthood and in cases of periventricular leukomalacia (PVL). We hypothesized that the developing brain is intrinsically vulnerable to excitotoxicity via maturation-specific NMDAR levels and subunit composition. In normal white matter, NR1 and NR2B levels were highest in the preterm period compared with adult. In gray matter, NR2A and NR3A expression were highest near term. NR2A was significantly elevated in PVL white matter, with reduced NR1 and NR3A in gray matter compared with uninjured controls. These data suggest increased NMDAR-mediated vulnerability during early brain development due to an overall upregulation of individual receptors subunits, in particular, the presence of highly calcium permeable NR2B-containing and magnesium-insensitive NR3A NMDARs. These data improve understanding of molecular diversity and heterogeneity of NMDAR subunit expression in human brain development and supports an intrinsic prenatal vulnerability to glutamate-mediated injury; validating NMDAR subunit-specific targeted therapies for PVL.

Electronic fetal monitoring in the United States: temporal trends and adverse perinatal outcomes

OBJECTIVE

To examine trends in electronic fetal monitoring (EFM) use and quantify the extent to which such trends are associated with changes in rates of primary cesarean delivery and neonatal morbidity and mortality.

METHODS

We carried out a retrospective study of more than 55 million nonanomalous singleton live births (24-44 weeks of gestation) delivered in the United States between 1990 and 2004. Changes in the risks of neonatal mortality, cesarean delivery, and operative vaginal delivery for fetal distress, 5-minute Apgar score lower than 4, and neonatal seizures (at 34 weeks of gestation or after) were examined in relation to changes in EFM use.

RESULTS

Electronic fetal monitoring use increased from 73.4% in 1990 to 85.7% in 2004, a relative increase of 17% (95% confidence interval 16-18%). This increase was associated with an additional 5% and 2% decline in early and late neonatal deaths, respectively, at 24-33 weeks of gestation as well as a 4-7% additional decline in the 5-minute Apgar score lower than 4 at 24-33, 34-36, and 37-44 weeks of gestation. Increasing EFM use was associated with a 2-4% incremental increased rate of both cesarean delivery and operative vaginal delivery for fetal distress at 24-33, 34-36, and 37-44 weeks of gestation. Increasing EFM was not associated with any temporal changes in the rate of neonatal seizures.

CONCLUSIONS

The temporal increase in EFM use in the United States appears to be modestly associated with the recent declines in neonatal mortality, especially at preterm gestations.

LEVEL OF EVIDENCE

II.

Vulnerability of the developing brain to hypoxic-ischemic damage: contribution of the cerebral vasculature to injury and repair?

As clinicians attempt to understand the underlying reasons for the vulnerability of different regions of the developing brain to injury, it is apparent that little is known as to how hypoxia-ischemia may affect the cerebrovasculature in the developing infant. Most of the research investigating the pathogenesis of perinatal brain injury following hypoxia-ischemia has focused on excitotoxicity, oxidative stress and an inflammatory response, with the response of the developing cerebrovasculature receiving less attention. This is surprising as the presentation of devastating and permanent injury such as germinal matrix-intraventricular haemorrhage (GM-IVH) and perinatal stroke are of vascular origin, and the origin of periventricular leukomalacia (PVL) may also arise from poor perfusion of the white matter. This highlights that cerebrovasculature injury following hypoxia could primarily be responsible for the injury seen in the brain of many infants diagnosed with hypoxic-ischemic encephalopathy (HIE). Interestingly the highly dynamic nature of the cerebral blood vessels in the fetus, and the fluctuations of cerebral blood flow and metabolic demand that occur following hypoxia suggest that the response of blood vessels could explain both regional protection and vulnerability in the developing brain. However, research into how blood vessels respond following hypoxia-ischemia have mostly been conducted in adult models of ischemia or stroke, further highlighting the need to investigate how the developing cerebrovasculature responds and the possible contribution to perinatal brain injury following hypoxia. This review discusses the current concepts on the pathogenesis of perinatal brain injury, the development of the fetal cerebrovasculature and the blood brain barrier (BBB), and key mediators involved with the response of cerebral blood vessels to hypoxia.