Sleep Electroencephloagram in Infants born Moderate to Late Preterm and Association with Subsquent Neurodevelopment.

Objectives: To compare among infants born moderate to late preterm (MLP) and full-term their neurophysiological sleep patterns on electroencephalogram (EEG) and to evaluate the association of sleep EEG findings 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 corrected age. Sleep spindles were manually annotated. Sleep macrostructure (ie, total sleep and sleep stages durations, and latencies to sleep and REM) was assessed. EEG spectral power and coherence were quantified. These features were compared between 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 to 6.50] minutes, P<0.001), had higher NREM power on delta 1 (MLP: 702.49 [557.46-840.67] μV²; term-born: 593.34 [449.21-749.36] μV², P=0.011] and delta 2 (MLP: 245.31 [194.17-327.77] μV², term-born: 215.32 [164.78-283.39] μV², p=0.028) and diverging coherence. NREM delta 1 and 2 spectral power were positively associated with personal-social-emotional development (partial Spearman correlation (r_s)=0.25, P=0.009 and r_s=0.25, P=0.011, respectively) and gross motor development (r_s=0.21, P=0.028 and r_s=0.20, P=0.036, respectively). Some parameters of intra- and inter-hemispherical 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, likely reflecting early differences in brain organization and function. These different sleep features in infants born MLP compared with those at term may indicate divergent trends in brain maturation.