Background and aims Prematurity and intrauterine growth restriction (IUGR) is associated with deviations of the developmental trajectory of the brain. We aimed to examine resting state networks (RSNs) in preterm infants with and without IUGR during natural sleep at 12 months.

Methods We included 30 preterm infants (<34 weeks) without focal brain lesions (12 with IUGR and 18 appropriate for gestational age) and 20 born-term infants that were scanned at 12 months during natural sleep. Structural and functional MRI was acquired in a 3T scanner. To account for head movement we performed frame censoring of the data. RSNs were computed using the MELODIC module (FSL software). Dual regression analysis was used to query between--group differences in RSNs.

Results Overall, the degree of movement on functional data was small. In the group we identified nine RSNs encompassing bilaterally the primary visual cortex, auditory cortex, sensori-motor cortex, lateral parietal cortex, precuneus, frontal and a sub-cortical network. Preterm infants had a more prominent cerebellar network compared to term infants. The three groups showed a fragmentized default-mode network. No significant differences were found between groups.

Conclusions The spatial patterns of the RSNs observed in preterm and term infants corresponded closely to those observed in adults. These findings may suggest that IUGR and prematurity does not interfere with the normal process of functional brain network development at 12 months of age. The fact that we could not find differences in RSNs does not rule out that alterations could occur later in development.