To determine the impact of fetal growth on postnatal amplitude-integrated electroencephalography (aEEG) and power spectrum electroencephalography (EEG) data in preterm infants born with intrauterine growth restriction (IUGR).

We defined IUGR as birth weight <10th percentile, and control as birth weight appropriate for gestational age (GA). We performed single-channel (C3-C4) EEG during the first 48 hours of life and measured the upper and lower margins of the aEEG trace width. EEG readings were analyzed by spectral analysis, and the relative power of the frequency bands was calculated. The Lacey Assessment of the Preterm Infant was administered before discharge.

We enrolled 14 infants with IUGR (mean GA, 34.3 ± 1.8 weeks; mean birth weight 1486 ± 304 g) and 16 appropriate for GA controls (mean GA, 33.7 ± 2 weeks; mean birth weight, 1978 ± 488 g). There were no significant between-group differences in perinatal complications. The mean aEEG trace width was 20.8 ± 1.4 μv in the infants with IUGR versus 17.3 ± 1.6 μv in controls (P < .001). The infants with IUGR also had significantly greater delta frequency activity and decreased theta, alpha, and beta frequency activities compared with controls. Delta frequency activity decreased with increasing GA (r = −0.8; P = .001 for infants with IUGR and r = −0.9; P < .001 for controls). The Lacey Assessment of the Preterm Infant developmental score was significantly lower in the infants with IUGR (P < .02) and was correlated with aEEG trace width (r = −0.6; P = .002) and with delta activity (r = −0.5; P = .02).

Preterm infants with IUGR have delayed EEG maturation associated with delayed neuromotor development. The predictive value of these alterations regarding developmental deficits associated with IUGR remains undetermined, however.