Cooling in Mild Encephalopathy Trial

The COMET trial is a multi-centre randomised controlled study evaluating whether cooling therapy (whole-body hypothermia) can safely improve cognitive outcomes in babies with mild Hypoxic-Ischaemic Encephalopathy (HIE).

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The COMET trial is part of the CONNECTIONS Consortium for Neonatal Neuroprotection and Time-Critical Trials, a collaborative network uniting hospitals and research teams across the UK and internationally to advance early interventions for newborn brain injury and improve lifelong outcomes. Mild HIE affects around 0.5 to 1 in every 1,000 newborns. Though traditionally considered low risk, recent research shows many affected infants face lasting cognitive and neurological challenges. COMET investigates whether early therapeutic cooling — already standard for moderate to severe HIE — can safely reduce these risks in babies with mild HIE. The results will help guide future neonatal care and improve long-term outcomes for vulnerable infants.

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Hypothermia Update: From the Horse’s Mouth

An international symposium uniting PIs from landmark hypothermia RCTs and global experts to review 20 years of evidence in therapeutic hypothermia for HIE, underline the importance of high-quality trials in safe clinical practice, and explore future directions in neonatal neuroprotection.

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Trial Documents

Access and download the latest protocol, PIS, and ICF.

Trial Support

Book a 15 min drop-in trial support Teams call with the COMET team

HIE Staging

A video guide to the Expanded Modified Sarnat staging

Book Training

For Certification in Expanded Modified Sarnat staging

Parent Information Video

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Parent Information Video

This short video explains the COMET study in clear, simple language for parents whose baby has shown signs of mild hypoxic-ischaemic encephalopathy (mild HIE). It outlines why the study is being done, what participation involves, and what treatments your baby may receive. The video has been co-developed with parents and neonatal staff to help families make informed decisions about taking part in the study.

Diagram showing the three pillars of the COMET trial: standardised neurological assessments, use of the e-Screener at the first neurological assessment, and early consent conversations with parents. Together these pillars support accurate diagnosis, real-time trial support, and informed parental decision-making.

Training and certification in neurological assessment ensure reliable assessments by trained clinicians. Over 800 clinicians have completed training, with sites encouraged to expand certification to all staff involved.

The e-Screener is used in real time during the first neurological examination of babies meeting Criteria A to minimise errors in HIE staging and alert the central trial team for immediate support. Video recording is recommended for babies not recruited to COMET to reduce misclassification of mild HIE but is not mandatory for recruited babies.

Early parental engagement includes providing a brief clinical update during CFM, explaining what is being monitored and how normal or abnormal patterns guide next steps. Parents are introduced to standard cooling or the COMET trial as appropriate, with emphasis on uncertainty, parental choice, and randomisation between cooling and normothermia.

Publications in Neonatal Encephalopathy

Explore our group’s peer-reviewed research on neonatal brain injury, with a focus on HIE, biomarkers, imaging, and neuroprotection.

View featured research outputs using the links below.

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