Safety and Efficacy of Hypothermia to Treat Neonatal Hypoxic-Ischemic Encephalopathy

Inclusion Criteria: * Age up to 6 hours * Gestational age ≥ 36 weeks and birth weight ≥ 2500 g * Apgar score ≤ 3 at 1 minute and ≤ 5 at 5 minutes, and/or cord blood gas pH \< 7.0 or base deficit ≤ 16 mmol/L, and/or need for resuscitation or ventilation at 5 minutes of age * Clinical signs of encephalopathy (seizures, coma, abnormal muscle tone and irregular breathing, etc) Exclusion Criteria: * Major congenital abnormalities * Infection * Other etiology of induced brain injury * Severe anemia (Hb \< 120 g/L) Eligible infants assessed for the severity of HIE according to criteria of the Neonatal Association of Chinese Academy of Pediatrics 25 modified from Sarnat and Sarnat 26 in 1986