Safety and Short-Term Outcomes of Therapeutic Hypothermia in Preterm Neonates 34-35 Weeks Gestational Age with Hypoxic-Ischemic Encephalopathy

Objective To evaluate the safety and short-term outcomes of preterm neonates born at 34-35 weeks gestation with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia. Study design Medical records of preterm neonates born at 34-35 weeks gestational age with HIE treated with therapeutic hypothermia were retrospectively reviewed. Short-term safety outcomes and the presence, severity (mild, moderate, severe), and patterns of brain injury on magnetic resonance imaging were reviewed using a standard scoring system, and compared with a cohort of term neonates with HIE treated with therapeutic hypothermia. Results Thirty-one preterm and 32 term neonates were identified. Therapeutic hypothermia-associated complications were seen in 90% of preterm infants and 81.3% of term infants (P = .30). In the preterm infants, hyperglycemia (58.1% vs31.3%, P = .03) and rewarming before completion of therapeutic hypothermia (19.4% vs 0.0%, P = .009) were more likely compared with term infants. All deaths occurred in the preterm group (12.9% vs 0%, P = .04). Neuroimaging showed the presence of injury in 80.6% of preterm infants and 59.4% of term infants (P = .07), with no differences in injury severity. Injury to the white matter was more prevalent in preterm infants compared with term infants (66.7% vs 25.0%, P = .001). Conclusions Therapeutic hypothermia in infants born at 34-35 weeks gestational age appears feasible. Risks of mortality and side effects warrant caution with use of therapeutic hypothermia in preterm infants.