Children born with perinatal asphyxia encephalopathy who received moderate hypothermia therapy showed superior neurocognitive outcomes at ages 6-7 years, compared with children who instead received usual care after birth, according to a report published online July 9 in the New England Journal of Medicine.
In the Total Body Hypothermia for Neonatal Encephalopathy (TOBY) trial published in 2009, investigators found that affected neonates who had been treated with moderate (33-34° C) hypothermia using cooling blankets for 72 hours showed a lower rate of cerebral palsy and higher scores on measures of mental development, psychomotor development, and gross motor function when they reached 18 months of age than did a control group that received usual care.
To determine whether these benefits persisted longer term, they followed up 184 of these children at the age of 6-7 years, said Dr. Denis Azzopardi of the Centre for the Developing Brain at King’s College London and his associates (N. Engl. J. Med. 2014;371:140-9).
The 98 children in the intervention group and 86 in the control group were assessed by a psychologist and a pediatrician blinded to the study-group assignments who performed neurologic and neuropsychological examinations encompassing sensory function, cognition, memory, attention, and executive function. Parents and teachers also completed questionnaires regarding the children’s behavior, memory, and use of health care and educational services.
The primary outcome – frequency of survival with an IQ score of 85 or higher – was 52% in the hypothermia group, compared with only 39% in the control group. In addition, a significantly higher proportion of children in the hypothermia group (77%) than in the control group (63%) had IQ scores of 85 or higher. Significantly more children in the hypothermia group (45%) than the control group (28%) survived without neurologic abnormalities and had better scores on measures of gross motor function and manual ability, the investigators said.
"In conclusion, our study provides evidence that the benefits of moderate hypothermia after perinatal asphyxia persist into middle childhood," Dr. Azzopardi and his associates wrote.
This study was supported by the U.K. Medical Research Council, the National Institute for Health Research Biomedical Research Centres at Imperial College London, the University of Oxford, and King’s College London. Dr. Azzopardi reported no potential financial conflicts of interest; one of his associates reported receiving personal fees unrelated to this study from Novartis and Shire, and another reported receiving governmental research grants unrelated to this study.