Determining the Effect of Birth Weight on Therapeutic Hypothermia in Neonates with Hypoxic-Ischemic Encephalopathy

We examine the effect of birth weight (BW) for gestational age (GA) on the temperatures reached during the treatment of neonatal hypoxic-ischemic encephalopathy (HIE) with therapeutic hypothermia (TH).

Retrospective data of 1,736 neonates with HIE who received TH were extracted from the Canadian Neonatal Network database for neonates admitted from 2010 to 2017. Neonates were stratified into three BW groups: small for GA < 10th centile, large for GA > 90th centile, and according to GA 10th to 89th centile at a given gestation using Canadian population data norms.

There was no significant difference in the lowest temperature reached, the likelihood of overshooting temperatures < 32.5°C during TH, or the change of encephalopathy stages among the three groups.

BW for GA did not appear to influence the temperatures neonates reached during hypothermia or encephalopathy stage following TH.

· Therapeutic hypothermia is well tolerated irrespective of weight for age. · SGA infants achieved and maintained target temperature similar to AGA and LGA babies. · Change in the Sarnat stage after hypothermia was similar across all birth weight groups.