Cooling Newborns Reduces Disability

Lowering the body temperature of full-term newborns to about 92oF within the first six hours can reduce the chance of disability and death among infants who do not receive enough oxygen or blood to the brain during birth, according to a new study reported in the October 13, 2005, issue of The New England Journal of Medicine.

When an infant's brain fails to receive sufficient oxygen or blood before birth, hypoxic ischemic encephalopathy (HIE) may occur hours before birth or during labor and delivery. This can be caused by compression of the placenta, tearing of the placenta from the uterine wall before birth, compression of the umbilical cord, or rupture of the uterus. HIE occurs about 0.5 to 1 times every thousand births. According to the study's authors, 10% of infants with moderate HIR die, as do 60% of those with severe HIE.

Prior studies in laboratory animals suggested that cooling the brain from 2-5oC after HIE could reduce death and disability. In the current study, researchers enrolled 208 full-term infants from 15 centers who had experienced oxygen deprivation during birth, assigning them either to a group with experimental cooling or a group receiving standard care. The experimental group infants were cooled by placing them on a soft blanket through which cool water circulated that lowered the temperature of the infants to 92.3oF. They remained on the blanket for 72 hours, and were then gradually warmed to normal body temperature.

When the doctors examined the infants at 18-22 months of age, 44% of those in the cooling group developed moderate to severe disability or died, compared to 62% in the control group.

"Physicians need to exercise extreme caution in putting the study's result into practice,” said Rose Higgins, M.D., program scientist for the U.S. National Institute of Child Health and Human Development (NICHD, Bethesda, MD, USA), which conducted the study. Most newborn intensive care units do not have the resources or personnel to duplicate the conditions of the study, she observed.