Objective To determine the incidence of hypoglycemia among infants with hypoxic-ischemic encephalopathy (HIE) who received therapeutic hypothermia (TH), and to assess whether infants with hypoglycemia had more brain injury on magnetic resonance imaging (MRI) or differences in neurodevelopmental outcome.
Study design Single-center, retrospective cohort study including infants cooled for HIE. Hypoglycemia (blood glucose <36.0 mg/dL <2 hours and <46.8 mg/dL ≥2 hours after birth) was analyzed in the period prior to brain MRI. Brain injury was graded using a validated score. Motor and neurocognitive outcomes were assessed at two years for all survivors, and 5.5 years for a subset who had reached this age.
Results Of 223 infants analyzed, 79 (35.4%) had hypoglycemia. MRI was performed in 187 infants. Infants with hypoglycemia (n=65) had higher brain injury scores (p=0.018). After adjustment for HIE severity, hypoglycemia remained associated with higher injury scores (3.6 points higher, 95% CI 0.8 to 6.4). Hyperglycemia did not affect MRI scores. In survivors at 2 years (n=154) and 5.5 years (n=102) univariable analysis showed lower 2-year motor scores, and lower motor and cognitive scores at preschool age in infants with hypoglycemia. After adjustment for HIE severity, infants with hypoglycemia had 9 points lower intelligence quotients (p=0.023) and higher odds of adverse
outcomes at preschool age (3.6, 95% CI 1.4 to 9.0).
Conclusions More than one third of infants cooled for HIE had hypoglycemia. These infants had a higher degree of brain injury on MRI and lower cognitive function at preschool age. Strategies toavoid hypoglycemia should be optimized in this setting.