Intra- and Extrauterine Maturation of Amplitude-integrated Electroencephalographic Activity in Preterm Infants Younger Than 30 Weeks of Gestation

Objective: To prospectively investigate the longitudinal changes of amplitude-integrated electroencephalographic (aEEG) activity in preterm infants <30 weeks gestational age (GA).

Methods: Infants (GA <30 weeks) without evidence of neurological abnormalities had weekly aEEG recordings performed. The relative duration of the three aEEG patterns (discontinuous low voltage, discontinuous high voltage and continuous) was determined and the influence of GA and postnatal age (PNA) on the occurrence of each pattern was assessed.

Results: Ninety-eight infants (median GA 26 weeks; range 23-29 weeks) were studied. With higher GA (OR 1.68, 95% CI 1.33-2.13) and PNA (OR 1.91, 95% CI 1.53-2.38), the likelihood for the occurrence of continuous activity increased. The discontinuous low-voltage pattern was less likely to occur with increasing GA (OR 0.68, 95% CI 0.55-0.83) and PNA (OR 0.70, 95% CI 0.61-0.81).

Conclusion: Maturation of aEEG activity in preterm infants is influenced by both GA and PNA.