The effects of betamethasone on the amplitude integrated EEG of infants born at 34- or 35-weeks gestation

Objective Assess if maternal betamethasone administration at 34–35 weeks accelerated neonatal amplitude integrated EEG (aEEG) maturation. Study design Nested, observational cohort in 7 centers participating in the Antenatal Late Preterm Steroid randomized trial. Up to 2 aEEGs were obtained in neonates born from 34 0 –35 6 weeks gestation before 72 h (aEEG 1) and at 5–7 days (aEEG 2) if hospitalized. Personnel and aEEG central readers were masked to the intervention. The primary outcome was maturation reflected by cycle frequency; secondary outcomes were border voltage, span, and discontinuity. Results 58 neonates were enrolled (betamethasone, 28, placebo, 30). On aEEG 1, cycle frequency did not differ, but betamethasone exposed infants had a greater lower border voltage and a broader span. On aEEG 2, both groups displayed increases in lower border voltage. Conclusions Betamethasone associated changes in lower border voltage support accelerated electrical activity. Further investigation is needed to understand the broader span.