Abstract: Background: Hypothermia treatment is now effective treatment for hypoxic ischemic encephalopathy (HIE). Currently, there is still no consensus on enteral nutrition to infants with HIE during therapeutic hypothermia at home and abroad. Objective: To study the safety of enteral nutrition during hypothermia treatment for HIE in neonates. Design: Retrospective non-randomized controlled study. Methods: Neonates with HIE undergoing hypothermia at the Department of neonatology, Children's Hospital of Chongqing Medical University between January 2019 to June 2020 were included in the study. According to whether patients received enteral nutrition during hypothermia treatment, they were divided into enteral nutrition (EN) group and unfed group. Data of general conditions, clinical manifestations, laboratory examinations, diagnosis, treatment, age of starting feeds, type, volume, and mode of enteral nutrition were collected. Main outcome measures: Incidence of neonatal necrotizing enterocolitis (NEC) during hospitalization. Results: A total of 95 patients with HIE were included in the analysis, including 51 patients in the EN group and 44 patients in the unfed group. Patients in the EN group had lower incidence of abdominal distension than the unfed group (P=0.047) and there were no significant differences in the incidence of vomiting, bloody stools, and convulsion between the two groups. No statistically significant differences were found in blood gas analysis measured within an hour of birth, first blood routine test after admission, intracranial hemorrhage in brain sonography, and abnormalities in cranial magnetic resonance between the two groups. Patients in the EN group had a shorter mean length of parenteral nutrition and hospital stay compared with the unfed group (P<0.001). There were no significant differences between the two groups regarding complications such as NEC and feeding intolerance. In the EN group, 60.8% received formula and 41.1% were fed on day 1 of life. The mean total volume was 19.1 mL·kg-1 over a 24 hour period and 68.6% did not increase feeds during hypothermia treatment. One patient developed NEC (I), and improved after conservative medical therapy. No deaths occurred. Conclusion: Early minimal enteral nutrition during hypothermia was associated with lower incidence of abdominal distension, a shorter mean length of parenteral nutrition and hospital stay, but did not increase incidence of NEC.

Key words: Neonate, Hypothermia, Enteral nutrition