104 - Therapeutic Hypothermia for Preterm Infants 34-35 weeks Gestational Age with Neonatal Encephalopathy

Sunday, April 30, 2023

3:30 PM – 6:00 PM ET

Poster Number: 104
Publication Number: 104.336

Seh-Hyun Kim, Brigham Women's Hospital, CHESTNUT HILL, MA, United States; Hoda El-Shibiny, BWH, Boston, MA, United States; Terrie Inder, Childrens Hospital of Orange County, Irvine, CA, United States; Mohamed El-Dib, Harvard Medical School, Boston, MA, United States

Presenting Author(s)

Seh-Hyun Kim, MD, PhD (he/him/his)

Research Fellow
Brigham Women's Hospital
CHESTNUT HILL, Massachusetts, United States

Background: Therapeutic hypothermia (TH) is the gold standard treatment of moderate and severe neonatal encephalopathy. Numerous centers provide TH to infants born at 36 weeks gestational age (GA) or more due to the lack of recommendations of TH in preterm infants at younger gestation. Our center (Brigham and Women’s Hospital) has routinely provided TH for infants as young as 34 weeks GA.

Objective: This study aims to evaluate the short-term outcomes and safety of TH in preterm infants at 34-35 weeks GA who received TH.

Design/Methods: This matched retrospective cohort study included 20 preterm infants at 34-35 weeks GA who received TH and 40 infants at 36 weeks GA or more who received TH between the years 2015-2021. The two groups were matched by Apgar score at 5 min, the worst base deficit on blood gas, and the worse neonatal encephalopathy score within a calendar year. Short-term outcomes including seizures, blood transfusions, subcutaneous fat necrosis, mortality, and intraventricular hemorrhage (IVH) by magnetic resonance imaging, were compared among groups.

Results: During the study period, seven infants were cooled at 34 weeks GA, and 13 were cooled at 35 weeks GA. (Table 1) Short-term outcomes of preterm infants at 34-35 weeks GA who received TH were comparable with infants at 36 weeks or more GA who received TH, regarding seizures (10.0% vs 15.0%, P = 0.893), blood transfusions (35.0% vs 25.0%, P = 0.613), subcutaneous fat necrosis (5.0% vs 2.5%, P = 1.000), mortality (0% vs 5%, P = 0.799) and IVH (30.0% vs 10.0%, P = 0.111). These findings were consistent when short-term outcomes were adjusted for GA and birthweight; seizures (aOR 1.081, 95% CI 0.871-1.341), blood transfusions (aOR 0.954, 95% CI 0.805-1.131), subcutaneous fat necrosis (aOR 0.845, 95% CI 0.559-1.277), mortality (aOR 1.071, 95% CI 0.708-1.619) and IVH (aOR 1.044, 95% CI 0.853-1.277).

Conclusion(s): There were no differences in short-term outcomes between preterm infants at 34-35 weeks GA and infants at 36 weeks or more GA who received TH. TH in preterm infants at 34-35 weeks GA is feasible in our study population. These results are limited by the small sample size and lack of long term follow up data. Results of randomized controlled trials are still needed to confirm safety as well as efficacy at younger gestation.