Preemie Hypothermia for Neonatal Encephalopathy

Most clinical studies of neonatal encephalopathy (NE) and potential interventions have focused on infants ≥36 weeks GA. Although many interventions have been suggested and assessed for prevention or palliation of NE, the only one currently supported by rigorous clinical evidence to improve outcome in human newborns has been hypothermia implemented at \<6 hours of postnatal age and maintained for 72 hrs. Data about diagnosis, frequency, severity, and outcome of NE in infants 33-35 weeks GA are sparse. This trial will assess safety and effectiveness of whole body hypothermia for 72 hours in preterm infants 33-35 weeks gestational age (GA) who present at \<6 hrs postnatal age with moderate to severe neonatal encephalopathy. Infants 33 0/7 to 35 6/7 weeks GA (best obstetrical estimate) and greater than or equal to 1500 grams birth weight (selected to minimize potential difficulties placing esophageal probe) who meet clinical, biochemical and neurologic criteria for moderate to severe NE will be randomized to either whole body hypothermia or participate in a non-cooled control group. The primary outcome will be death or moderate to severe disability at 18-22 months corrected age. The presence or absence of disability will be determined by the standard NRN interdisciplinary follow-up exam. Secondary Study includes determining an association between MRI detectable injury and neurodevelopment at 18-22 months.