Maternal risk factors for adverse outcome in asphyxiated newborns treated with hypothermia: parity and labor duration matter

Abstract

Introduction

Perinatal asphyxia remains a frequent cause of neonatal mortality and long-term neurodevelopmental sequelae, despite the introduction of therapeutic hypothermia. Specific maternal characteristics may predispose asphyxiated newborns treated with hypothermia to worse outcome.

Objective

To investigate the possible association between specific maternal factors and adverse outcome in asphyxiated newborns treated with hypothermia.

Methods

We conducted a retrospective review of our database of 215 asphyxiated newborns treated with hypothermia from 2008 to 2015. We collected maternal characteristics including parity and labor duration, and we defined adverse outcome as death and/or brain injury. We compared the maternal characteristics between the asphyxiated newborns who developed adverse outcome and those who did not.

Results

Asphyxiated newborns born to nulliparous mothers had a significantly higher risk of adverse outcome (61%), compared to asphyxiated newborns born from primiparous (19%) and multiparous (20%) mothers (p = .002). Labor duration was longer in nulliparous mothers (p = .04). Among mothers who delivered vaginally, labor duration was significantly longer in newborns developing adverse outcome (p = .04). In multivariable analysis, parity was confirmed as an independent predictor of adverse outcome in all newborns, but labor duration showed a borderline non-significant association with adverse outcome (p = .051) only in newborns born vaginally. Labor duration beyond 12 h of life was associated with maximal sensitivity and specificity in detecting asphyxiated newborns at an increased risk of adverse outcome despite hypothermia treatment (AUC 0.62, p = .044).

Conclusions

Newborns with evidence of perinatal asphyxia, born to nulliparous mothers, and especially to those in whom the duration of labor has been prolonged, might be at higher risk of death or brain injury despite the use of therapeutic hypothermia.

Keywords:

• Labor duration
• magnetic resonance imaging
• neonatal encephalopathy
• parity
• perinatal asphyxia

Acknowledgments

We thank Mr. Wayne Ross Egers for his professional English correction of the manuscript. Pia Wintermark receives research grant funding from the FRSQ Clinical Research Scholar Career Awards Junior 2, and a Canadian Institutes of Health Research (CIHR) Project Grant.

Disclosure statement

No potential conflict of interest was reported by the authors. This manuscript has been contributed to, seen, and approved by all the authors. All the authors fulfill the authorship credit requirements.

Additional information

Funding

Pia Wintermark receives research grant funding from the FRSQ Clinical Research Scholar Career Awards Junior 2, and a Canadian Institutes of Health Research (CIHR) Project Grant. The study sponsors had no involvement in the study design, the collection, analysis, and interpretation of data, the writing of the report, or the decision to submit the paper for publication.