Mild hypoxic ischaemic encephalopathy and long term neurodevelopmental outcome - A systematic review

Abstract

Aims: Hypoxic ischaemic encephalopathy (HIE) remains a significant cause of long term neurodisability despite therapeutic hypothermia (TH). Infants with mild HIE, representing 50% of those with HIE, are perceived as low risk and are currently not eligible for TH [1]. This review examines the available evidence of outcome in term infants with mild HIE.

Methods: Medline, Embase and Cochrane Clinical Trials databases were searched in March 2017. Studies with well-defined HIE grading at birth and standardised neurodevelopmental assessment at ≥18 months were included. Abnormal outcome was defined as death, cerebral palsy or standardised neurodevelopmental test score more than 1 standard deviation below the mean.

Result: Twenty studies were included. Abnormal outcome was reported in 86/341 (25%) of infants. There was insufficient evidence to examine the effect of TH on outcome.

Conclusion: A significant proportion of infants with mild HIE have abnormal outcome at follow up.

Keywords: Hypoxic ischaemic encephalopathy (HIE); Neurodevelopmental outcome; Therapeutic hypothermia (TH).