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.

Consensus definition and diagnostic criteria for neonatal encephalopathy-study protocol for a real-time modified delphi study.

BACKGROUND: 'Neonatal encephalopathy' (NE) describes a group of conditions in term infants presenting in the earliest days after birth with disturbed neurological function of cerebral origin. NE is aetiologically heterogenous; one cause is peripartum hypoxic ischaemia. Lack of uniformity in the terminology used to describe NE and its diagnostic criteria creates difficulty in the design and interpretation of research and complicates communication with families. The DEFINE study aims to use a modified Delphi approach to form a consensus definition for NE, and diagnostic criteria. METHODS: Directed by an international steering group, we will conduct a systematic review of the literature to assess the terminology used in trials of NE, and with their guidance perform an online Real-time Delphi survey to develop a consensus diagnosis and criteria for NE. A consensus meeting will be held to agree on the final terminology and criteria, and the outcome disseminated widely. DISCUSSION: A clear and consistent consensus-based definition of NE and criteria for its diagnosis, achieved by use of a modified Delphi technique, will enable more comparability of research results and improved communication among professionals and with families. IMPACT: The terms Neonatal Encephalopathy and Hypoxic Ischaemic Encephalopathy tend to be used interchangeably in the literature to describe a term newborn with signs of encephalopathy at birth. This creates difficulty in communication with families and carers, and between medical professionals and researchers, as well as creating difficulty with performance of research. The DEFINE project will use a Real-time Delphi approach to create a consensus definition for the term 'Neonatal Encephalopathy'. A definition formed by this consensus approach will be accepted and utilised by the neonatal community to improve research, outcomes, and parental experience.

Association of Primary Language with Very Low Birth Weight Outcomes in Hispanic Infants in California.

OBJECTIVE: To determine the association of Spanish as a primary language for a family with the health outcomes of Hispanic infants with very low birth weight (VLBW, <1500g). STUDY DESIGN: Data from the California Perinatal Quality Care Collaborative (CPQCC) linked to hospital discharge records were analyzed. Hispanic infants with VLBW born between 2009 and 2018 with a primary language of English or Spanish were included. Outcomes selected were hypothesized to be sensitive to language barriers. Multivariable logistic regression models and mixed models estimated associations between language and outcomes. RESULTS: Of 18 364 infants meeting inclusion criteria, 27% (n = 4976) were born to families with Spanish as a primary language. In unadjusted analyses, compared with infants of primarily English-speaking families, these infants had higher odds of hospital readmission within 1 year (OR 1.11 [95% CI 1.02-1.21]), higher odds to receive human milk at discharge (OR 1.32 [95% CI 1.23-1.42]), and lower odds of discharge home with oxygen (OR 0.83 [95% CI 0.73-0.94]). In multivariable analyses, odds of readmission and home oxygen remained significant when adjusting for infant but not maternal and hospital characteristics. Higher odds for receipt of any human milk at discharge were significant in all models. Remaining outcomes did not differ between groups. CONCLUSIONS: Significant differences exist between Hispanic infants with VLBW of primarily Spanish-vs English-speaking families. Exploration of strategies to prevent readmissions of infants of families with Spanish as a primary language is warranted.

Risk of seizures in neonates with hypoxic-ischemic encephalopathy receiving hypothermia plus erythropoietin or placebo.

BACKGROUND: An ancillary study of the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial for neonates with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia examined the hypothesis that neonates randomized to receive erythropoietin (Epo) would have a lower seizure risk and burden compared with neonates who received placebo. METHODS: Electroencephalograms (EEGs) from 7/17 HEAL trial centers were reviewed. Seizure presence was compared across treatment groups using a logistic regression model adjusting for treatment, HIE severity, center, and seizure burden prior to the first dose. Among neonates with seizures, differences across treatment groups in median maximal hourly seizure burden were assessed using adjusted quantile regression models. RESULTS: Forty-six of 150 (31%) neonates had EEG seizures (31% in Epo vs 30% in placebo, p = 0.96). Maximal hourly seizure burden after the study drug was not significantly different between groups (median 11.4 for Epo, IQR: 5.6, 18.1 vs median 9.7, IQR: 4.9, 21.0 min/h for placebo). CONCLUSION: In neonates with HIE treated with hypothermia who were randomized to Epo or placebo, we found no meaningful between-group difference in seizure risk or burden. These findings are consistent with overall trial results, which do not support Epo use for neonates with HIE undergoing therapeutic hypothermia. IMPACT: In the HEAL trial of erythropoietin (Epo) vs placebo for neonates with encephalopathy presumed due to hypoxic-ischemic encephalopathy (HIE) who were also treated with therapeutic hypothermia, electrographic seizures were detected in 31%, which is lower than most prior studies. Epo did not reduce the proportion of neonates with acute provoked seizures (31% in Epo vs 30% in placebo) or maximal hourly seizure burden after the study drug (median 11.4, IQR 5.6, 18.1 for Epo vs median 9.7, IQR 4.9, 21.0 min/h for placebo). There was no anti- or pro-convulsant effect of Epo when combined with therapeutic hypothermia for HIE.

Cardiac Dysfunction in Neonatal HIE Is Associated with Increased Mortality and Brain Injury by MRI.

OBJECTIVE: Describe the association between cardiac dysfunction and death or moderate-to-severe abnormalities on brain magnetic resonance imaging (MRI) in neonates undergoing therapeutic hypothermia for hypoxic ischemic encephalopathy (HIE). STUDY DESIGN: Retrospective study in neonates with moderate or severe HIE undergoing therapeutic hypothermia between 2008 and 2017. Primary outcome was death or moderate-to-severe brain injury using the Barkovich score. Conventional and speckle-tracking echocardiography measures were extracted from available echocardiograms to quantify right (RV) and left (LV) ventricular functions. RESULTS: A total of 166 newborns underwent therapeutic hypothermia of which 53 (36.5%) had echocardiography performed. Ten (19%) died prior to hospital discharge, and 11 (26%) had moderate-to-severe brain injury. There was no difference in chronologic age at echocardiography between the normal and adverse outcome groups (22 [±19] vs. 28 [±21] hours, p = 0.35). Cardiac findings in newborns with abnormal outcome included lower systolic and diastolic blood pressure (BP) at echocardiography (p = 0.004) and decreased tricuspid annular plane systolic excursion (a marker of RV systolic function; p = 0.01), while the ratio of systolic pulmonary artery (PA) pressure to systolic BP indicated isosystemic pressures (>2/3 systemic) in both groups. A multilogistic regression analysis, adjusting for weight and seizure status, indicated an association between abnormal outcome and LV function by longitudinal strain, as well as by ejection fraction. CONCLUSION: Newborns who died or had moderate-to-severe brain injury had a higher incidence of cardiac dysfunction but similar PA pressures when compared with those who survived with mild or no MRI abnormalities. KEY POINTS: · Newborns with HIE with functional LV/RV dysfunction are at risk for death or brain injury.. · All neonates with HIE had elevated pulmonary pressure, but neonates with poor outcome had RV dysfunction.. · When evaluating newborns with HIE by echocardiography, beyond estimation of pulmonary pressure, it is important to assess biventricular function..

Seizure Severity and Treatment Response in Newborn Infants with Seizures Attributed to Intracranial Hemorrhage.

OBJECTIVE: We sought to characterize intracranial hemorrhage (ICH) as a seizure etiology in infants born term and preterm. For infants born term, we sought to compare seizure severity and treatment response for multisite vs single-site ICH and hypoxic-ischemic encephalopathy (HIE) with vs without ICH. STUDY DESIGN: We studied 112 newborn infants with seizures attributed to ICH and 201 infants born at term with seizures attributed to HIE, using a cohort of consecutive infants with clinically diagnosed and/or electrographic seizures prospectively enrolled in the multicenter Neonatal Seizure Registry. We compared seizure severity and treatment response among infants with complicated ICH, defined as multisite vs single-site ICH and HIE with vs without ICH. RESULTS: ICH was a more common seizure etiology in infants born preterm vs term (27% vs 10%, P < .001). Most infants had subclinical seizures (74%) and an incomplete response to initial antiseizure medication (ASM) (68%). In infants born term, multisite ICH was associated with more subclinical seizures than single-site ICH (93% vs 66%, P = .05) and an incomplete response to the initial ASM (100% vs 66%, P = .02). Status epilepticus was more common in HIE with ICH vs HIE alone (38% vs 17%, P = .05). CONCLUSIONS: Seizure severity was greater and treatment response was lower among infants born term with complicated ICH. These data support the use of continuous video electroencephalogram monitoring to accurately detect seizures and a multistep treatment plan that considers early use of multiple ASMs, particularly with parenchymal and high-grade intraventricular hemorrhage and complicated ICH.

Response to antiseizure medications in neonates with acute symptomatic seizures.

In a prospective cohort of 534 neonates with acute symptomatic seizures, 66% had incomplete response to the initial loading dose of antiseizure medication (ASM). Treatment response did not differ by gestational age, sex, medication, or dose. The risk of incomplete response was highest for seizures due to intracranial hemorrhage and lowest for hypoxic-ischemic encephalopathy, although the difference was not significant after adjusting for high seizure burden and therapeutic hypothermia treatment. Future trial design may test ASMs in neonates with all acute symptomatic seizure etiologies and could target neonates with seizures refractory to an initial ASM.

Differences in patient characteristics and care practices between two trials of therapeutic hypothermia.

BACKGROUND: The Induced Hypothermia (IH) and Optimizing Cooling (OC) trials for hypoxic-ischemic encephalopathy (HIE) had similar inclusion criteria. The rate of death/moderate-severe disability differed for the subgroups treated with therapeutic hypothermia (TH) at 33.5 °C for 72 h (44% vs. 29%, unadjusted p = 0.03). We aimed to evaluate differences in patient characteristics and care practices between the trials. METHODS: We compared pre/post-randomization characteristics and care practices between IH and OC. RESULTS: There were 208 patients in the IH trial, 102 cooled, and 364 in the OC trial, 95 cooled to 33.5 °C for 72 h. In OC, neonates were less ill, fewer had severe HIE, and the majority were cooled prior to randomization. Differences between IH and OC were observed in the adjusted difference in the lowest PCO2 (+3.08 mmHg, p = 0.005) and highest PO2 (-82.7 mmHg, p < 0.001). In OC, compared to IH, the adjusted relative risk (RR) of exposure to anticonvulsant prior to randomization was decreased (RR 0.58, (0.40-0.85), p = 0.005) and there was increased risk of exposure during cooling to sedatives/analgesia (RR 1.86 (1.21-2.86), p = 0.005). CONCLUSION: Despite similar inclusion criteria, there were differences in patient characteristics and care practices between trials. Change in care practices over time should be considered when planning future neuroprotective trials.

Maternal or neonatal infection: association with neonatal encephalopathy outcomes.

This corrects the article DOI: 10.1038/pr.2014.47.

Development of a NeuroNICU with a Broader Focus on All Newborns at Risk of Brain Injury: The First 2 Years.

OBJECTIVE: Many critically ill neonates have an existing brain injury or are at risk of neurologic injury. We developed a "NeuroNICU" (neurologic neonatal intensive care unit) to better provide neurologically focused intensive care. STUDY DESIGN: Demographic and clinical variables, services delivered, and patient outcomes were recorded in a prospective database for all neonates admitted to the NeuroNICU between April 23, 2013, and June 25, 2015. RESULTS: In total, 546 neonates were admitted to the NeuroNICU representing 32% of all NICU admissions. The most common admission diagnoses were congenital heart disease (30%), extreme prematurity (18%), seizures (10%), and hypoxic-ischemic encephalopathy (9%). Neuromonitoring was common, with near-infrared spectroscopy used in 69%, amplitude-integrated electroencephalography (EEG) in 45%, and continuous video EEG in 35%. Overall, 43% received neurology or neurosurgery consultation. Death prior to hospital discharge occurred in 11%. Among survivors, 87% were referred for developmental follow-up, and among those with a primary neurologic diagnosis 57% were referred for neurology or neurosurgical follow-up. CONCLUSION: The NeuroNICU-admitted newborns with or at risk of brain injury comprise a high percentage of NICU volume; 38% had primary neurologic diagnoses, whereas 62% had medical diagnoses. We found many opportunities to provide brain focused intensive care, impacting a substantial proportion of newborns in our NICU.

Treatment Duration After Acute Symptomatic Seizures in Neonates: A Multicenter Cohort Study.

We aimed to define determinants of duration of treatment for acute symptomatic neonatal seizures in a contemporary multicenter observational cohort study. After adjustment for potential confounders, only study site and seizure etiology remained significantly associated with the chance of continuing antiseizure medication after discharge to home.

Contemporary Profile of Seizures in Neonates: A Prospective Cohort Study.

OBJECTIVE: To determine the contemporary etiology, burden, and short-term outcomes of seizures in neonates monitored with continuous video-electroencephalogram (cEEG). STUDY DESIGN: We prospectively collected data from 426 consecutive neonates (56% male, 88% term) ≤44 weeks' postmenstrual age with clinically suspected seizures and/or electrographic seizures. Subjects were assessed between January 2013 and April 2015 at 7 US tertiary care pediatric centers following the guidelines of the American Clinical Neurophysiology Society for cEEG for at-risk neonates. Seizure etiology, burden, management, and outcome were determined by chart review by the use of a case report form designed at study onset. RESULTS: The most common seizure etiologies were hypoxic-ischemic encephalopathy (38%), ischemic stroke (18%), and intracranial hemorrhage (11%). Seizure burden was high, with 59% having ≥7 electrographic seizures and 16% having status epilepticus; 52% received ≥2 antiseizure medications. During the neonatal admission, 17% died; 49% of survivors had abnormal neurologic examination at hospital discharge. In an adjusted analysis, high seizure burden was a significant risk factor for mortality, length of hospital stay, and abnormal neurological examination at discharge. CONCLUSIONS: In this large contemporary profile of consecutively enrolled newborns with seizures treated at centers that use cEEG per the guidelines of the American Clinical Neurophysiology Society, about one-half had high seizure burden, received ≥2 antiseizure medications, and/or died or had abnormal examination at discharge. Greater seizure burden was associated with increased morbidity and mortality. These findings underscore the importance of accurate determination of neonatal seizure frequency and etiology and a potential for improved outcome if seizure burden is reduced.

The Neurointensive Care Nursery and Evolving Roles for Nursing.

Neonatal neurocritical care is an emerging subspecialty that combines the expertise of critical care medicine and neurology with that of nursing and other providers in an interprofessional team approach to care. Neurocritical care of the neonate has roots in adult and pediatric practice. It has been demonstrated that adults with acute neurologic conditions who are treated in a specialized neurocritical care unit have reduced morbidity and mortality, as well as decreased length of stay, lower costs, and reduced need for neurosurgical procedures. In pediatrics, neurocritical care has focused on various primary and secondary neurologic conditions complicating critical care that also contribute to mortality, morbidity, and duration of hospitalization. However, the concept of neurocritical care as a subspecialty in pediatric practice is still evolving, and evidence demonstrating improved outcomes is lacking. In the neonatal intensive care nursery, neurocritical care is also evolving as a subspecialty concept to address both supportive and preventive care and optimize neurologic outcomes for an at-risk neonatal patient population. To enhance effectiveness of this care approach, nurses must be prepared to appropriately recognize acute changes in neurologic status, implement protocols that specifically address neurologic conditions, and carefully monitor neurologic status to help prevent secondary injury. The complexity of this team approach to brain-focused care has led to the development of a specialized role: the neurocritical care nurse (neonatal intensive care nursery [NICN] nurse). This article will review key concepts related to neonatal neurocritical care and the essential role of nursing. It will also explore the emerging role of the NICN nurse in supporting early recognition and management of at-risk infants in this neonatal subspecialty practice.

Diminished white matter injury over time in a cohort of premature newborns.

OBJECTIVES: To determine the rate of magnetic resonance imaging (MRI)-detected noncystic white matter injury (WMI) in a prospective cohort of premature newborns, and to evaluate its associations with changes in clinical predictors of WMI over the study period. STUDY DESIGN: A prospective cohort of premature newborns (<33 weeks gestational age) was studied with MRI within 4 weeks of birth and near term-equivalent age. A pediatric neuroradiologist scored the severity of WMI on T1-weighted MRI according to published criteria. WMI was classified as none/mild or moderate/severe. Subjects with severe cystic WMI, periventricular hemorrhagic infarction, or motion artifact on MRI were excluded. Changes in clinical characteristics and predictors of WMI over the study period (1998-2011) were evaluated. Predictors of moderate/severe WMI, including birth year, were evaluated using multivariate logistic regression. RESULTS: Among 267 newborns, 45 (17%) had moderate/severe WMI. The rate of moderate/severe WMI decreased over the study period (P = .002, χ(2) test for trends). On multivariate logistic regression, the odds of moderate/severe WMI decreased by 11% for each birth year of the cohort (OR, 0.89; 95% CI, 0.81-0.98; P = .02). Prolonged exposure to indomethacin also was independently associated with reduced odds of moderate/severe WMI. CONCLUSION: The decreasing burden of MRI-detected moderate/severe noncystic WMI in our cohort of premature newborns is independent over time of changes in the known clinical predictors of WMI. Prolonged exposure to indomethacin is associated with reduced WMI.

Maternal or neonatal infection: association with neonatal encephalopathy outcomes.

BACKGROUND: Perinatal infection may potentiate brain injury among children born preterm. The objective of this study was to examine whether maternal and/or neonatal infection are associated with adverse outcomes among term neonates with encephalopathy. METHODS: This study is a cohort study of 258 term newborns with encephalopathy whose clinical records were examined for signs of maternal infection (chorioamnionitis) and infant infection (sepsis). Multivariate regression was used to assess associations between infection, pattern, and severity of injury on neonatal magnetic resonance imaging, as well as neurodevelopment at 30 mo (neuromotor examination, or Bayley Scales of Infant Development, second edition mental development index <70 or Bayley Scales of Infant Development, third edition cognitive score <85). RESULTS: Chorioamnionitis was associated with lower risk of moderate-severe brain injury (adjusted odds ratio: 0.3; 95% confidence interval: 0.1-0.7; P = 0.004) and adverse cognitive outcome in children when compared with no chorioamnionitis. Children with signs of neonatal sepsis were more likely to exhibit watershed predominant injury than those without (P = 0.007). CONCLUSION: Among neonates with encephalopathy, chorioamnionitis was associated with a lower risk of brain injury and adverse outcomes, whereas signs of neonatal sepsis carried an elevated risk. The etiology of encephalopathy and timing of infection and its associated inflammatory response may influence whether infection potentiates or mitigates injury in term newborns.

Predictive performance of a gentamicin population pharmacokinetic model in neonates receiving full-body hypothermia.

BACKGROUND: Population pharmacokinetic (popPK) models derived from small pharmacokinetics (PK) studies in neonates are often underpowered to detect clinically important characteristics that drive dosing. External validation of such models is crucial. In this study, the predictive performance of a gentamicin popPK model in neonates receiving hypothermia was evaluated. METHODS: A previously published gentamicin popPK model was developed in neonates with hypoxic ischemic encephalopathy undergoing hypothermia using a retrospective single-institution (University of California-San Francisco) data set. The predictive performance of this model was evaluated in an external retrospective data set from the University of California-San Francisco (validation A) and another from Duke University (validation B). Both institutions used the same hypothermia protocol and collected similar clinical and PK data. Gentamicin dosing and samples were collected per routine care. Predictive performance was evaluated by quantifying the accuracy and precision of model predictions and using simulation-based diagnostics to detect bias in predictions. RESULTS: Forty-one neonates (n = 18 validation A; n = 23 validation B) with median (range) gestational age of 40 weeks (33-42) and birth weight of 3.3 kg (1.9-4.6) and 76 samples (55% troughs, 33% and 28% drawn at 24 and 36 hours after dose, respectively) were analyzed. The model adequately predicted gentamicin concentrations from the same institution (validation A; median average fold error = 1.1 and numerical prediction distribution error P > 0.05) but underpredicted concentrations from the outside institution (validation B; median average fold error = 0.6 and numerical prediction distribution error P < 0.05). CONCLUSIONS: The model demonstrated adequate predictive performance for an external data set in the same institution but not from an outside institution. Larger sample sizes, use of data from multiple institutions, and external evaluation in development of popPK models in neonates may improve generalizability of dosing recommendations arising from single-institution studies.

Evolution of the Sarnat exam and association with 2-year outcomes in infants with moderate or severe hypoxic-ischaemic encephalopathy: a secondary analysis of the HEAL Trial.

OBJECTIVE: To study the association between the Sarnat exam (SE) performed before and after therapeutic hypothermia (TH) and outcomes at 2 years in infants with moderate or severe hypoxic-ischaemic encephalopathy (HIE). DESIGN: Secondary analysis of the High-dose Erythropoietin for Asphyxia and EncephaLopathy Trial. Adjusted ORs (aORs) for death or neurodevelopmental impairment (NDI) based on SE severity category and change in category were constructed, adjusting for sedation at time of exam. Absolute SE Score and its change were compared for association with risk for death or NDI using locally estimated scatterplot smoothing curves. SETTING: Randomised, double-blinded, placebo-controlled multicentre trial including 17 centres across the USA. PATIENTS: 479/500 enrolled neonates who had both a qualifying SE (qSE) before TH and a SE after rewarming (rSE). INTERVENTIONS: Standardised SE was used across sites before and after TH. All providers underwent standardised SE training. MAIN OUTCOME MEASURES: Primary outcome was defined as the composite outcome of death or any NDI at 22-36 months. RESULTS: Both qSE and rSE were associated with the primary outcome. Notably, an aOR for primary outcome of 6.2 (95% CI 3.1 to 12.6) and 50.3 (95% CI 13.3 to 190) was seen in those with moderate and severe encephalopathy on rSE, respectively. Persistent or worsened severity on rSE was associated with higher odds for primary outcome compared with those who improved, even when qSE was severe. CONCLUSION: Both rSE and change between qSE and rSE were strongly associated with the odds of death/NDI at 22-36 months in infants with moderate or severe HIE.