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Characteristics and short-term outcomes of neonates with mild hypoxic-ischemic encephalopathy treated with hypothermia



To compare the characteristics and outcomes of neonates with mild hypoxic-ischemic encephalopathy (HIE) who received hypothermia versus standard care.

Study design

We conducted a retrospective cohort study of neonates ≥35 weeks’ gestation and ≥1800 g admitted with a diagnosis of Sarnat stage 1 encephalopathy. We evaluated length of hospital stay, duration of ventilation, evidence of brain injury on MRI, and neonatal morbidities.


Of 1089 eligible neonates, 393 (36%) received hypothermia and 595 (55%) had neuroimaging. The hypothermia group was more likely to be outborn, born via C-section, had lower Apgar scores, and required extensive resuscitation. They had longer durations of stay (9 vs. 6 days, P < 0.001), respiratory support (3 vs. 2 days, P < 0.001), but lower odds of brain injury on MRI (adjusted odds ratio 0.33, 95% CI: 0.22–0.52) compared with standard care group.


Despite prolongation of hospital stay, hypothermia may be potentially beneficial in neonates with mild HIE; however, selection bias cannot be ruled out.

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The authors gratefully acknowledge all site investigators and data abstractors of the Canadian Neonatal Network (CNN). We thank the staff at the Maternal-infant Care (MiCare) Research Centre at Mount Sinai Hospital, Toronto, Ontario, for organizational support of CNN. We also thank EWY, of MiCare, for assistance with the statistical analyses; Heather McDonald-Kinkaid, PhD, of MiCare, for editorial support in preparing this manuscript; and Ms Rosanna Yankanah, MSc, CCRP Manager, Clinical Research for assistance with the ethics submission.

Canadian Neonatal Network Investigators

Prakesh S. Shah8, Jaideep Kanungo9, Joseph Ting10, Zenon Cieslak11, Rebecca Sherlock12, Ayman Abou Mehrem13, Jennifer Toye14, Carlos Fajardo15, Zarin Kalapesi16, Jaya Bodani16, Koravangattu Sankaran17, Sibasis Daspal17, Mary Seshia18, Deepak Louis18, Ruben Alvaro19, Amit Mukerji20, Orlando Da Silva21, Mohammad Adie22, Kyong-Soon Lee23, Michael Dunn24, Brigitte Lemyre25, Faiza Khurshid26, Ermelinda Pelausa27, Keith Barrington28, Anie Lapoint28, Guillaume Ethier28, Christine Drolet29, Bruno Piedboeuf29, Martine Claveau30, Marc Beltempo30, Valerie Bertelle31, Edith Masse31, Roderick Canning32, Hala Makary33, Cecil Ojah34, Luis Monterrosa34, Julie Emberley35, Jehier Afifi36, Andrzej Kajetanowicz37, Shoo K. Lee38


Organizational support for the Canadian Neonatal Network was provided by the Maternal-infant Care (MiCare) Research Centre at Mount Sinai Hospital in Toronto, Ontario, Canada. MiCare is supported by a team grant from the Canadian Institutes of Health Research (CIHR) (CTP 87518), by the Ontario Ministry of Health and Long-Term Care, and by the participating hospitals. PSS holds an Applied Research Chair in Reproductive and Child Health Services and Policy Research from the CIHR (APR-126340).

Author information





IRG conceptualized and designed the study, designed the data collection instruments, collected data, carried out the initial analyses, and drafted, reviewed, and revised the paper. HW reviewed the initial study proposal and research ethics application, contributed to the acquisition and interpretation of data, and reviewed and revised the paper. PW, KM, SS, and DL contributed to the interpretation of data and critically reviewed and revised the paper. EWY contributed to the analysis and interpretation of data and revised the paper. PSS conceptualized and designed the study, coordinated and supervised the data collection, and critically reviewed and revised the paper for important intellectual content. As corresponding author, PSS confirms that he has had full access to the data in the study and final responsibility for the decision to submit for publication.

Corresponding author

Correspondence to Prakesh S. Shah.

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The authors declare that they have no conflict of interest.

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The members of the Canadian Neonatal Network Investigators are listed below the Acknowledgements.

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Goswami, I.R., Whyte, H., Wintermark, P. et al. Characteristics and short-term outcomes of neonates with mild hypoxic-ischemic encephalopathy treated with hypothermia. J Perinatol 40, 275–283 (2020).

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