Therapeutic hypothermia for treating neonatal encephalopathy ineffective for some newborns

Reviewed by Emily Henderson, B.Sc.Apr 28 2023

Therapeutic hypothermia, the only evidence-based treatment for newborns born with neonatal encephalopathy (NE) at or after 36 weeks, is not effective for reducing death or moderate/severe disability in newborns born between 33 and 35 weeks, according to a new study. The research will be presented at the Pediatric Academic Societies (PAS) 2023 Meeting, held April 27-May 1 in Washington, D.C.

Researchers examined the effectiveness of whole-body therapeutic hypothermia-;a commonly used treatment to lower newborns' body temperature and protect against the effects of moderate or severe NE-;in younger newborns. NE is a brain condition experienced at or near birth, often caused by reduced oxygen to the brain. While evidence supports the use of therapeutic hypothermia for newborns born at 36 weeks or later, many clinicians use the treatment for infants at 35 weeks' gestation or less.

The trial enrolled 168 newborns born between 33-36 weeks who had NE. Half of these newborns received therapeutic hypothermia, while the other half maintained a normal temperature for 72 hours. Trial participants received a brain MRI at seven to 21 days and neuro-developmental testing with hearing and vision assessment at 18-22 months.

Researchers found a 77% probability of increased death compared to newborns for whom researchers maintained a normal temperature. The researchers found no evidence that therapeutic hypothermia reduced the combined outcome of death or moderate/severe disability among trial participants. Outcomes were assessed at 18-22 months old.

Despite no evidence supporting its use in younger newborns, clinicians continue to use therapeutic hypothermia in newborns younger than 36 weeks. These study findings are clear: therapeutic hypothermia is ineffective in more premature newborns."

Roger G. Faix, M.D., professor of pediatrics/neonatology at the University of Utah and presenting author

The trial, which was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health, was conducted in 16 Neonatal Research Network NICUs between 2015 and 2020.