Sleep Electroencephalogram in Infants Born Moderate to Late Preterm and Association with Subsequent Neurodevelopment

Objective: To compare electroencephalographic (EEG) sleep patterns among infants born moderate to late preterm (MLP) and full-term and to evaluate the association of sleep EEG findings in both groups with subsequent neurodevelopment. Study design: Infants enrolled at Cork University Maternity Hospital underwent a daytime sleep EEG at 4 months and Griffiths III developmental assessment at 18 months of corrected age. Sleep spindles were manually annotated. Sleep macrostructure (ie, total sleep and sleep stage durations, and latencies to sleep and rapid eye movement [REM]) was assessed. EEG spectral power and coherence were quantified. These features were compared between the groups. Associations between sleep features differing between groups and Griffiths III scores were investigated. Results: The mean (SD) gestational ages for infants born MLP (30/59 females) and term (40/96 females) were 34.5 (1.3) and 39.8 (1.2) weeks, respectively. Both groups showed similar sleep spindle features. Infants born MLP had shorter stage N2 sleep duration (MLP: median [IQR] of 2.75 [1.88-4.63]; term-born: 4.50 [2.50-6.50] minutes, P < .001), had higher non-REM (NREM) power on delta 1 (MLP: 702.49 [557.46-840.67] μV²; term-born: 593.34 [449.21-749.36] μV², P = .011] and delta 2 (MLP: 245.31 [194.17-327.77] μV², term-born: 215.32 [164.78-283.39] μV², P = .028) and diverging coherence. NREM delta 1 and 2 spectral power were positively associated with personal-social-emotional development (partial Spearman correlation (partial r_s) = 0.25, P = .009 and partial r_s = 0.25, P = .011, respectively) and gross motor development (partial r_s = 0.21, P = .028 and partial r_s = 0.20, P = .036, respectively). Some parameters of intrahemispherical and interhemispherical coherence were also correlated with Griffiths III subscales of development. Conclusions: Analyzing multiple sleep EEG features at 4 months corrected age, we identified alterations in sleep biomarkers of infants born MLP compared to those born full term, likely reflecting early differences in brain organization and function and, may indicate divergent trends in brain maturation.