Neurocognitive Outcomes at Age 2 Years after Neonatal Hypoglycemia in a Cohort of Participants from the hPOD Randomized Trial

Abstract

Importance: Neonatal hypoglycemia is common, but its association with later neurodevelopment is uncertain. Objective: To examine associations between neonatal hypoglycemia and neurocognitive outcomes at corrected age 2 years. Design, Setting, and Participants: Exploratory cohort analysis of the Hypoglycaemia Prevention With Oral Dextrose (hPOD) randomized clinical trial was conducted. The trial recruited participants from January 9, 2015, to May 5, 2019, with follow-up between January 26, 2017, and July 31, 2021. Infants were recruited from 9 maternity hospitals in New Zealand and assessed at home or in a research clinic. Children born late preterm and at term at risk of neonatal hypoglycemia but without evidence of acute or imminent illness in the first hour after birth were screened and treated to maintain blood glucose concentrations greater than or equal to 47 mg/dL. Exposures: Hypoglycemia was defined as any blood glucose concentration less than 47 mg/dL, recurrent as 3 or more episodes, and severe as less than 36 mg/dL. Main Outcomes and Measures: Neurologic examination and tests of development (Bayley III) and executive function. The primary outcome was neurosensory impairment (any of the following: blindness, deafness, cerebral palsy, developmental delay, or executive function total score worse than 1.5 SD below the mean). Results: A total of 1197 of 1321 (91%) eligible children were assessed at a mean of corrected age 24 months; 616 (52%) were male. Compared with the normoglycemia group, children who experienced hypoglycemia were more likely to have neurosensory impairment (111 [23%] vs 125 [18%]; adjusted risk ratio [aRR], 1.28; 95% CI, 1.01-1.60), particularly if they experienced severe episodes (30 [28%] vs 125 [18%]; aRR, 1.68; 95% CI, 1.20-2.36), but not recurrent episodes (12 [19%] vs 125 [18%]; aRR, 1.06; 95% CI, 0.63-1.80). The risk of cognitive, language, or motor delay was similar between groups, but children who experienced hypoglycemia had lower Bayley-III composite cognitive (adjusted mean difference [aMD], -1.48; 95% CI, -2.79 to -0.18) and motor scores (aMD, -2.05; 95% CI, -3.30 to -0.79). Conclusions and Relevance: In children born at risk of hypoglycemia but otherwise well, those who experienced neonatal hypoglycemia were more likely to have neurosensory impairment at corrected age 2 years, with higher risks after severe episodes. Further research is required to determine causality..