Neonatal hypoxic-ischemic encephalopathy in apparently low risk pregnancies: Retrospective analysis of the last five years at the University of Bologna

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Antepartum and intrapartum risk factors for neonatal hypoxic-ischemic encephalopathy: a systematic review with meta-analysis

PURPOSE OF REVIEW

To review literature about risk factors of neonatal hypoxic-ischemic encephalopathy (HIE).

RECENT FINDINGS

Search in PubMed, MEDLINE, Embase, Clinicaltrials.gov and reference lists from 1999 to 2018.

INCLUSION CRITERIA

study population composed of neonates who manifested HIE within 28 days from delivery, data reported as proportional rate. Studies were excluded if they included preterm pregnancies, postnatal conditions leading to HIE and/or fetal malformations, focused on a single risk factor, were not in English language. PRISMA guidelines were followed. Interstudies heterogeneity was assessed and a random/fixed models were generated as appropriate. Comparison between neonates with HIE vs. controls was performed by calculating odds ratio-95% confidence interval (OR-95% CI). Differences were significant if 95% CI did not encompass 1. Twelve articles were included. Fetuses with growth restriction (OR: 2.87; 95% CI: 1.77-4.67), nonreassuring cardiotocography (OR: 6.38; 95% CI: 2.56-15.93), emergency cesarean section (OR: 3.69; 95% CI: 2.75-4.96), meconium (OR: 3.76; 95% CI: 2.58-5.46) and chorioamnionitis (OR: 3.46: 95% CI: 2.07-5.79) were at higher risk of developing HIE. Nulliparity, gestational diabetes, hypertension, oligohydramnios, polyhydramnios, male sex, induction of labor, labor augmentation, premature rupture of membrane, and vacuum delivery were not significantly different.

SUMMARY

Neonatal HIE has multifactorial origin and its cause is often undetermined and not preventable.PROSPERO (Registration number: CRD42018106563).

Perinatal mortality or severe neonatal encephalopathy among normally formed singleton pregnancies according to obstetric risk status:" is low risk the new high risk?" A population-based cohort study

OBJECTIVE

To evaluate the capacity of the current system of obstetric risk stratification at the outset of pregnancy to predict severe adverse perinatal outcome.

STUDY DESIGN

This retrospective cohort study of singleton pregnancies over a five year period (2009-2013) was performed at the Rotunda Hospital, Dublin, Ireland. High-risk or low-risk status was assigned retrospectively to a large consecutive cohort of women with a normally-formed singleton pregnancy on the basis of factors analyzed at the first prenatal hospital visit. The incidence of severe perinatal morbidity and mortality were compared between high- and low-risk groups to determine the predictive utility of risk stratification at the outset of pregnancy for severe perinatal morbidity.

RESULTS

During the study period, 41,044 patients registered for prenatal care. 25,702;(63%) were deemed low-risk and 15,342;(37%) high-risk. Low-risk women were statistically more likely to be nulliparous (p < 0.0001) and to have a spontaneous or operative vaginal delivery (p < 0.0001). High-risk women were more likely to be multiparous and to undergo Caesarean delivery (p < 0.0001). The perinatal mortality rate was 3.8 per-1000 in low-risk pregnancies and 6.1 per-1000 in the a priori high-risk group (p = 0.012). The incidence of severe neonatal encephalopathy (NNE) was 1.8 and 0.65 per-1000 in the low and high-risk groups respectively (p = 0.0025).

CONCLUSION

Where low-risk status is assigned at registration, neonatal encephalopathy is more prevalent. This data is relevant for the design of prenatal care models and demonstrates that assignment of low obstetric risk on the basis of maternal or pre-pregnancy factors alone may erroneously be interpreted as conferring low-risk status to the fetus.

Congenital cerebral palsy and prenatal exposure to self-reported maternal infections, fever, or smoking

OBJECTIVE

The objective of the study was to investigate the association between maternal self-reported infections, fever, and smoking in the prenatal period and the subsequent risk for congenital cerebral palsy (CP).

STUDY DESIGN

We included the 81,066 mothers of singletons born between 1996 and 2003 who participated in the Danish National Birth Cohort. Children were followed up through December 2008. Information on maternal infections, fever, smoking, and other demographic and lifestyle factors during pregnancy were reported by mothers in computer-assisted telephone interviews in early and midgestation. We identified 139 CP cases including 121 cases of spastic CP (sCP) as confirmed by the Danish National Cerebral Palsy Register. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Self-reported vaginal infections were associated with an increased risk of CP and sCP (aHR, 1.52; 95% CI, 1.04-2.24; and aHR, 1.73; 95% CI, 1.16-2.60, respectively) and particularly untreated vaginal infections were associated with an increased risk of sCP (aHR, 1.95; 95% CI, 1.16-3.26). Fever was associated with the risk of CP (aHR, 1.53; 95% CI, 1.06-2.21). Smoking 10 or more cigarettes per day during pregnancy was also associated with sCP (aHR, 1.80; 95% CI, 1.10-2.94). There was a modest excess in risk for children exposed to both heavy smoking and vaginal infections. No other self-reported infections were significantly associated with CP.

CONCLUSION

Self-reported vaginal infections, fever, and smoking 10 or more cigarettes per day during pregnancy were associated with a higher risk of overall CP and/or sCP.