Abstract

Objective: Therapeutic hypothermia is the standard neuroprotective treatment for neonates with hypoxic-ischemic encephalopathy (HIE). However, neurodevelopmental outcomes may still vary depending on the severity of encephalopathy. This study aimed to evaluate two-year neurodevelopmental outcomes in infants with HIE treated with therapeutic hypothermia and compare outcomes between Stage 2 and Stage 3 cases classified according to the Sarnat & Sarnat staging system.

Material and Methods: We conducted a retrospective cross-sectional study including 138 infants born at ≥35 weeks of gestation who were diagnosed with HIE and received therapeutic hypothermia in a Level III NICU between January 2016 and December 2017. Neurodevelopment was assessed at 24 months using the Bayley Scales of Infant and Toddler Development-II (BSID-II), focusing on Mental Development Index (MDI) and Psychomotor Development Index (PDI) scores.

Results: Infants in the Stage 3 group required significantly more respiratory support, had a higher frequency of aEEG abnormalities, and more often received anticonvulsant therapy (p=0.020, p<0.001 and p<0.001, respectively). The Stage 3 group had significantly lower mean MDI and PDI scores (84±10 and 71±11, respectively) than the Stage 2 group (89±17 and 94±18; p=0.049 and p=0.001). Neurodevelopmental impairment was more prevalent in Stage 3 patients (36.5% vs. 17.3%, p=0.012).

Conclusion:  Despite uniform application of therapeutic hypothermia, neurodevelopmental outcomes at 24 months differ significantly by HIE severity. These findings highlight the importance of timely intervention, individualized follow-up, and the need for additional strategies in managing severe HIE cases.

Keywords: Hypothermia, hypoxic-ischemic encephalopathy, newborn

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Copyright © 2025 The Author(s). This is an open access article distributed under the Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is properly cited.

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1.
Küçükoğlu Keser M, Kadıoğlu Şimşek G, Beşer E, Okman E, Kanmaz Kutman HG. Two-year neurodevelopmental outcomes after therapeutic hypothermia in neonatal hypoxic-ischemic encephalopathy: a retrospective cohort study. Turk J Pediatr Dis [Internet]. 2025 Jul. 28 [cited 2025 Aug. 6];19(4):203-8. Available from: https://turkjpediatrdis.org/article/view/1151