Chorioamnionitis and neonatal encephalopathy in term infants with fetal acidemia: histopathologic correlations

Association between decreased cord blood inter-alpha inhibitor levels and neonatal encephalopathy at birth

BACKGROUND

Inter-alpha inhibitor proteins (IAIPs) are structurally related proteins found in the systemic circulation with immunomodulatory anti-inflammatory properties. Reduced levels are found in inflammatory related conditions including sepsis and necrotizing enterocolitis, and in neonatal rodents after exposure to hypoxia ischemia. In the current study, cord blood IAIP levels were measured in neonates with and without exposure to hypoxic-ischemic encephalopathy (HIE).

METHODS

This is a prospective cohort study including infants born ≥36 weeks over a one-year period. Term pregnancies were divided into two groups: a "reference control" (uncomplicated term deliveries), and "moderate to severe HIE" (qualifying for therapeutic hypothermia). IAIPs were quantified using a sensitive ELISA on the cord blood samples.

RESULTS

The study included 57 newborns: Reference control group (n = 13) and moderate/severe HIE group (n = 44). Measurement of IAIP cord blood concentrations in moderate to severe HIE group [278.2 (138.0, 366.0) μg/ml] revealed significantly lower IAIP concentrations compared with the control group [418.6 (384.5, 445.0) μg/ml] (p = 0.002).

CONCLUSIONS

These findings suggest a potential role for IAIPs as indicators of neonates at risk for HIE. IAIP levels could have diagnostic implications in the management of HIE. Future research is required to explore the relationship between HIE and IAIPs as biomarkers for disease severity.

CATEGORY OF STUDY

Translational.

Placental pathology as a marker of brain injury in infants with hypoxic ischemic encephalopathy

BACKGROUND

Hypoxic Ischemic Encephalopathy (HIE) can lead to devastating consequences for the affected infant. Although therapeutic cooling benefits infants with moderate and severe HIE, differentiating mild from moderate-severe HIE may be challenging. The placenta reflects the fetal intrauterine environment and may reveal underlying processes that affect brain injury.

AIM

To describe placental histopathology using the Amsterdam Placental Workshop Group Criteria in different grades of HIE.

STUDY DESIGN

Retrospective cohort.

SUBJECTS

Infants admitted to a tertiary care neonatal intensive care unit with a diagnosis of HIE between 2011 and 2016.

OUTCOME MEASURE

Maternal and neonatal clinical variables and placental histopathology using the Amsterdam Placental Workshop Group Criteria were compared between mild and moderate-severe HIE. Mann-Whitney or t-test or ꭓ² were performed for bivariate associations as appropriate. To explain the relationship between placental pathology and severity of HIE odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using logistic regression models.

RESULTS

Of the 73 infants in the study, 23 had mild and 50 moderate-sever HIE. There was no difference in maternal and neonatal characteristics except for sentinel events which were higher in the moderate- severe group. On placental histopathology, acute inflammation, including fetal inflammatory reaction (FIR) were significantly higher in the moderate-severe group. After adjusting for confounders, FIR remained significantly associated with moderate-severe HIE, ORs 6.29, 95 % CI 1.5-25.

CONCLUSION

Our study demonstrates FIR in the placenta is associated with severity of HIE.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02811263.

Epidural analgesia, intrapartum hyperthermia, and neonatal brain injury: a systematic review and meta-analysis

BACKGROUND

Epidural analgesia is associated with intrapartum hyperthermia, and chorioamnionitis is associated with neonatal brain injury. However, it is not known if epidural hyperthermia is associated with neonatal brain injury. This systematic review and meta-analysis investigated three questions: (1) does epidural analgesia cause intrapartum hyperthermia, (2) is intrapartum hyperthermia associated with neonatal brain injury, and (3) is epidural-induced hyperthermia associated with neonatal brain injury?

METHODS

PubMed, ISI Web of Knowledge, The Cochrane Library, and Embase were searched from inception to January 2020 using Medical Subject Headings (MeSH) terms relating to epidural analgesia, hyperthermia, labour, and neonatal brain injury. Studies were reviewed independently for inclusion and quality by two authors (Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach). Two meta-analyses were performed using the Mantel-Haenszel fixed effect method to generate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-one studies were included for Question 1 (646 296 participants), 36 for Question 2 (11 866 021 participants), and two studies for Question 3 (297 113 participants). When the mode of analgesia was randomised, epidural analgesia was associated with intrapartum hyperthermia (OR: 4.21; 95% CI: 3.48-5.09). There was an association between intrapartum hyperthermia and neonatal brain injury (OR: 2.79; 95% CI: 2.54-2.3.06). It was not possible to quantify the association between epidural-induced hyperthermia and neonatal brain injury.

CONCLUSIONS

Epidural analgesia is a cause of intrapartum hyperthermia, and intrapartum hyperthermia of any cause is associated with neonatal brain injury. Further work is required to establish if epidural-induced hyperthermia is a cause of neonatal brain injury.

Neonatal Encephalopathy: Need for Recognition of Multiple Etiologies for Optimal Management

Neonatal encephalopathy (NE) is associated with high mortality and morbidity. Factors predisposing to NE can be antenatal, perinatal, or a combination of both. Antenatal maternal factors, familial factors, genetic predisposition, hypoxic ischemic encephalopathy, infections, placental abnormalities, thrombophilia, coagulation defects, and metabolic disorders all have been implicated in the pathogenesis of NE. At present, therapeutic hypothermia is the only treatment available, regardless of etiology. Recognizing the etiology of NE involved can also guide investigations such as metabolic and sepsis workups to ensure optimal management. Understanding the etiology of NE may allow the development of targeted adjunctive therapies related to the underlying mechanism and develop preventative strategies.

Antenatal and Intrapartum Risk Factors for Hypoxic-Ischemic Encephalopathy in a US Birth Cohort

OBJECTIVE

To identify risk factors for hypoxic-ischemic encephalopathy (HIE) within a recent US birth cohort.

STUDY DESIGN

In a retrospective cohort study of 44 572 singleton infants ≥36 weeks of gestation born at Kaiser Permanente Northern California in 2008-2015, we identified all infants with HIE based on the presence of 3 inclusion criteria: clinical signs of neonatal encephalopathy, NICU admission, and either a 10-minute Apgar of ≤5 or a base excess of ≤-15 mmol/L. Neonatal acidemia was defined as a base excess of ≤-12 mmol/L. We ascertained antenatal and intrapartum complications from electronic records. Multivariable analysis was performed using logistic regression.

RESULTS

There were 45 infants (1.0 per 1000) with HIE and 197 (4.4 per 1000) with neonatal acidemia. Of the infants with HIE, 64% had an intrapartum complication consisting of a sentinel event (36%), clinical chorioamnionitis (40%), or both (11%). Risk factors for HIE on multivariable analysis were sentinel event (relative risk [RR], 16.1; 95% CI, 8.4-33) and clinical chorioamnionitis (RR, 5.2; 95% CI, 2.7-9.9). After removing the 16 infants with HIE who were exposed to a sentinel event from multivariate analysis, maternal age of ≥35 years (RR, 2.5; 95% CI, 1.1-5.6) and a urinary tract infection during pregnancy (RR, 2.6; 95% CI, 1.0-6.5) emerged as potential antenatal risk factors for HIE.

CONCLUSIONS

A significant proportion of HIE is preceded by a sentinel event, emphasizing the importance of developing improved methodologies to predict and prevent this perinatal complication. Strategies focused on reducing other complications such as clinical chorioamnionitis and/or maternal pyrexia may also improve our ability to prevent HIE.

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.

Umbilical arterial pH in patients with cerebral palsy

BACKGROUND

Umbilical arterial pH (UApH) in severe cerebral palsy (CP) is not fully understood.

AIMS

This work aims to determine the relationship between fetal acidemia and clinical features of severe CP.

STUDY DESIGN

A retrospective study design is used.

SUBJECTS

A review was conducted unti1 April 2013 among 218 infants with CP diagnosed to be caused by antenatal and/or intrapartum conditions determined by the Japan Council for Quality Health Care. After excluding patients in whom the causes of CP were thought to be due to events after delivery, 168 infants born at over 34weeks of gestation that both Apgar score and UApH were measured were selected.

OUTCOME MEASURES

Severe fetal acidemia was defined as a pH of less than 7.0.

RESULTS

Six major factors were found to be associated with CP: placental abruption (A, n=42), traumatic delivery with an abnormal FHR pattern (B, n=29), an abnormal FHR pattern during labor (C, n=27), chorioamnionitis with an abnormal FHR pattern (D, n=17), an abnormal FHR pattern before labor (E, n=14), and cord prolapse (F, n=10). The UApH was less than 7.0 in 114 cases (67.9%) and more than 7.20 in 20 cases (11.9%). The UApH values were lowest in group A (median 6.7, 6.43-6.99) and highest in group E (7.18, 6.92-7.45). The distribution of the UApH values was significantly different in these groups.

CONCLUSION

Placental abruption was a factor most associated with low pH. Even among the infants with severe CP, over 10% of patients exhibited a non-acidemic status at birth.

Why the term neonatal encephalopathy should be preferred over neonatal hypoxic-ischemic encephalopathy

The unresponsiveness of the full-term newborn is sometimes attributed to asphyxia, even when no severe physiologic disturbance occurred during labor and delivery. The controversy about whether to use the name "hypoxic-ischemic encephalopathy" or "newborn encephalopathy" has recently flared in publications directed toward pediatricians and neurologists. In this clinic opinion piece, I discuss the importance to obstetricians of this decision and explain why "newborn encephalopathy" should be the default term.

Placental infarction identified by macroscopic examination and risk of cerebral palsy in infants at 35 weeks of gestational age and over

OBJECTIVE

We sought to investigate whether placental infarction determined by macroscopic examination was associated with risk of cerebral palsy (CP).

STUDY DESIGN

This was a population-based study of macroscopic placental infarcts in singletons>35 weeks' gestational age, in 158 perinatal deaths, 445 infants with CP, and 491 controls matched with CP cases for gestational age.

RESULTS

Placental infarcts were recorded in 2.0% of controls, 4.4% of deaths (relative risk [RR], 2.2; 95% confidence interval [CI], 0.8-5.6]), 5.2% of infants with CP (P<.05, RR, 2.5; 95% CI, 1.2-5.3), and 8.4% with spastic quadriplegic CP (P=.0026; RR, 4.4; 95% CI, 1.8-10.6). In children with CP, unlike controls, placental infarction was associated with reduced fetal growth, older maternal age, more prior miscarriages, and poor neonatal condition, but not with maternal preeclampsia.

CONCLUSION

Placental infarction identified by macroscopic examination was associated with increased risk of CP and the CP subtype, spastic quadriplegic CP. Antecedents of placental infarction differed in children with CP compared with control children.

Placental pathology in asphyxiated newborns meeting the criteria for therapeutic hypothermia

OBJECTIVE

We sought to describe placental findings in asphyxiated term newborns meeting therapeutic hypothermia criteria and to assess whether histopathologic correlation exists between these placental lesions and the severity of later brain injury.

STUDY DESIGN

We conducted a prospective cohort study of the placentas of asphyxiated newborns, in whom later brain injury was defined by magnetic resonance imaging.

RESULTS

A total of 23 newborns were enrolled. Eighty-seven percent of their placentas had an abnormality on the fetal side of the placenta, including umbilical cord lesions (39%), chorioamnionitis (35%) with fetal vasculitis (22%), chorionic plate meconium (30%), and fetal thrombotic vasculopathy (26%). A total of 48% displayed placental growth restriction. Chorioamnionitis with fetal vasculitis and chorionic plate meconium were significantly associated with brain injury (P = .03). Placental growth restriction appears to significantly offer protection against the development of these injuries (P = .03).

CONCLUSION

Therapeutic hypothermia may not be effective in asphyxiated newborns whose placentas show evidence of chorioamnionitis with fetal vasculitis and chorionic plate meconium.

The relationship between intrapartum maternal fever and neonatal acidosis as risk factors for neonatal encephalopathy

OBJECTIVES

This study was undertaken to investigate the relationship among maternal intrapartum fever, neonatal acidosis, and the risk of neonatal encephalopathy.

STUDY DESIGN

Cohort study of pregnancies at term. Logistic regression was used to estimate the effect of maternal fever and acidosis on the risk of neonatal encephalopathy. The potential interaction between maternal fever and acidosis was included in the models.

RESULTS

Of 8299 women, 25 neonates (0.3%) had encephalopathy develop. These were more often born acidotic (adjusted odds ratio 11.5; 95% CI, 5.0-26.5) or after a maternal intrapartum fever (adjusted odds ratio 8.1; 95% CI, 3.5-18.6). Where both risk factors coexisted, the risk was 12.5% (adjusted odds ratio 93.9; 95% CI, 28.7-307.2). Although this effect is multiplicative, there was no evidence of statistical interaction (P = .93); the effect of maternal fever on the risk of encephalopathy was similar in infants with (adjusted odds ratio 8.7; 95% CI, 2.4-31.7) and without acidosis (adjusted odds ratio 7.4; 95% CI, 2.4-21.9).

CONCLUSION

The combination of a maternal fever with cord acidosis greatly increases the risk of neonatal encephalopathy, but there is evidence against interaction between them, suggesting that they represent 2 separate causal pathways.