Peripartum events associated with severe neurologic morbidity and mortality among acidemic neonates

Risk factors for unfavorable outcome at discharge of newborns with hypoxic-ischemic encephalopathy in the era of hypothermia

OBJECTIVE

To re-visit short-term outcomes and associated risk factors of newborns with hypoxic-ischemic encephalopathy (HIE) in an era where hypothermia treatment (HT) is widespread.

METHODS

This is a prospective population-based cohort in French neonatal intensive care units (NICU). Neonates born at or after 34 weeks of gestational age with HIE were included; main outcomes were in-hospital death and discharge with abnormal or normal MRI. Associations of early perinatal risk factors, present at birth or at admission to NICU, with these outcomes were studied.

RESULTS

A total of 794 newborns were included and HT was administered to 670 (84.4%); 18.3% died and 28.5% and 53.2% survived with abnormal and normal MRI, respectively. Severe neurological status, Apgar score at 5 mn ≤5, lactate at birth ≥11 mMoles/l, and glycemia ≥100 mg/dL at admission were associated with an increased risk of death (relative risk ratios (aRRR) (95% CI) 19.93 (10.00-39.70), 2.89 (1.22-1.62), 3.06 (1.60-5.83), and 2.55 (1.38-4.71), respectively). Neurological status only was associated with survival with abnormal MRI (aRRR (95% CI) 1.76 (1.15-2.68)).

CONCLUSION

Despite high use of HT in this cohort, 46.8% died or presented brain lesions. Early neurological and biological examinations were associated with unfavorable outcomes and these criteria could be used to target children who warrant further neuroprotective treatment.

TRIAL REGISTRATION

Clinical trial registry, NCT02676063, ClinicalTrials.gov.

IMPACT

In this population-based cohort of newborns with HIE where 84% received hypothermia, 46.8% still had an unfavorable evolution (death or survival with abnormal MRI). Risk factors for death were high lactate, low Apgar score, severe early neurological examination, and high glycaemia. While studies have established risk factors for HIE, few have focused on early perinatal factors associated with short-term prognosis. This French population-based cohort updates knowledge about early risk factors for adverse outcomes in the era of widespread cooling. In the future, criteria associated with an unfavorable evolution could be used to target children who would benefit from another neuroprotective strategy with hypothermia.

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).

Intrapartum fetal monitoring and perinatal risk factors of neonatal hypoxic-ischemic encephalopathy

BACKGROUND

Neonatal hypoxic-ischemic encephalopathy (HIE) in term infants, is a major cause of neonatal mortality and severe neurologic disability.

OBJECTIVES

To identify in labor fetal monitoring characteristic patterns and perinatal factors associated with neonatal HIE.

STUDY DESIGN

Single-center retrospective case-control study between 2010 and 2017. Cases clinically diagnosed with neonatal HIE treated by therapeutic hypothermia according to strict criteria (HIE-TH) were compared to a group of neonates born in the same period, gestational age-matched diagnosed with fetal distress according to fetal monitoring interpretation that was followed by prompt delivery, without subsequent HIE or therapeutic hypothermia (No-HIE). The primary outcome of the study was the electronic fetal monitoring (EFM) pattern during 60 min prior to delivery; the secondary outcome was the identification of perinatal associated factors.

RESULTS

54 neonates with HIE were treated by therapeutic hypothermia. EFM parameters most predictive of HIE-TH were indeterminate baseline heart rate OR = 47.297, 95% (8.17-273.76) p < 0.001, bradycardia OR = 15.997 95% (4.18-61.18) p < 0.001, low variability OR = 10.224, 95% (2.71-38.45) p < 0.001, higher baseline of the fetal heart rate calculated for each increment of 1 BPM OR = 1.0547, 95% (1.001-1.116) p = 0.047. Rupture of a previous uterine cesarean scar and placental abruption were characteristic of the HIE-TH group 14.8% vs. 1% p < 0.05; and 16.7% vs. 6% p < 0.05, respectively. Adverse neonatal outcomes also differed significantly: HIE-TH had a higher rate of neonatal seizures 46.2% vs. 0% p < 0.001 and mortality 7.7% vs. 0% p < 0.001.

CONCLUSIONS

Characteristic fetal monitoring pattern prior to delivery together with acute obstetric emergency events are associated with neonatal HIE, neurological morbidity, and mortality.

Adverse pregnancy outcomes and multiple nuchal cord loops

PURPOSE

To evaluate the effects of nuchal cord and the number of loops during labor and delivery on delivery outcomes among women with singleton pregnancy who delivered vaginally.

METHODS

This retrospective cohort study included 42,798 women with singleton, vertex, and vaginal deliveries at 24-43 weeks of gestation. We analyzed delivery outcomes based on the number of nuchal cord loops.

RESULTS

A total of 42,798 deliveries met the inclusion criteria, of which, 3809 (8.9%) had nuchal cord with 1 loop at delivery, 1035 (2.42%) had 2 loops, and 258 (0.6%) had 3 loops. Nuchal cord with 3 loops compared to no nuchal cord has been associated with higher incidence of intrauterine fetal death (1.9%), Apgar scores less than 7 at 1 and 5 min (7.4%, 2.3%), and higher rate of operative vaginal deliveries (17.5%). Nuchal cord with 2 or 3 loops was associated with higher incidence of intrauterine growth restriction (10.2%, 11.6%).  In a multiple logistic regression model, nuchal cord with 3 loops was an independent risk factor for operative vaginal delivery and Apgar score less than 7 in 1 min.

CONCLUSIONS

In the case of vaginal delivery in the presence of nuchal cord, as the number of nuchal cord loops increased, so did the number of adverse delivery outcomes. While 3 loops were associated with higher incidence of intrauterine fetal death, intrauterine growth restriction, increased operative vaginal deliveries, and low Apgar scores, 1 loop was not associated with adverse perinatal outcomes.