BACKGROUND: Preterm infants are at high risk for subsequent neurodevelopmental disability. Early developmental characterization of brain and neurobehavioral function is critical for identifying high-risk infants. This study aimed to elucidate the early evolution of sensorimotor function in preterm neonates by exploring postnatal age-related changes in the brain white matter (WM) and neurobehavioral abilities. METHODS: One hundred eighteen neonates without abnormalities on magnetic resonance imaging were included. Diffusion tensor imaging-derived fractional anisotropy (FA) and neonatal neurobehavioral assessment were separately used to characterize the brain WM microstructure and neurobehavioral development levels. Scatterplots with linear fitting and Pearson correlation were used to investigate the relationships of FA and neurobehavioral scores (active tone and behavior scores) with postnatal age separately for preterm and term neonates. Here, the optical radiation (OR), auditory radiation, corticospinal tract (CST), posterior thalamic radiation (PTR), and thalamus-primary somatosensory cortex were selected as the regions of interest (ROIs). RESULTS: The preterm FAs in the ROIs were lower than term neonates (all Bonferroni-corrected P <
0.001). Preterm CST FA showed a significantly higher correlation with postnatal age (P = 0.042) than term (r = 0.29 vs 0.08), whereas significantly higher correlations were found in term OR (P = 0.018) and PTR (P = 0.002). Similarly, relatively high and low correlations between active tone (r = 0.48 vs 0.35
P = 0.049 for interactions with a postnatal age ≥14 days and preterm/term group status) and behavioral scores (r = 0.36 vs 0.52
P = 0.030 for interactions of postnatal age and preterm/term group status) were observed in preterm infants. CONCLUSIONS: Although delayed, preterm neonates exhibit a "catch-up" pattern in motor development in the newborn stage.