The relationship between sonographically assessed volumetric brain development in VLBW preterm infants and neurodevelopmental outcome at 2 years of age-data from the NeoNEVS project

Very low birth weight (VLBW) preterm infants are at increased risk for long-term neurodevelopmental impairment. Early identification of infants at risk remains challenging, particularly with regard to dynamic brain development during neonatal intensive care. Cranial ultrasound (CUS) allows safe and repeated bedside assessment of cerebral growth over time.

In this retrospective cohort study, 79 VLBW infants (<1,500 g, <32 weeks gestation) treated at two tertiary neonatal intensive care units between 2019 and 2021 were included. Serial cranial ultrasound examinations were performed from birth to discharge. Total brain volume was estimated using a validated ellipsoid model, and individual cerebral growth rates were derived from longitudinal measurements. Neurodevelopmental outcome at 24 months corrected age was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III), reporting percentile ranks for cognitive, language, motor, and a combined developmental score. Associations were evaluated using Spearman correlation and multivariable linear regression.

The median cerebral brain growth rate was 2.4 cm³/day (95% CI: 1.5-3.1). Cerebral growth rate demonstrated a modest but statistically significant positive correlation with Bayley-III motor percentile rank (r = 0.25, p < 0.05). Associations with cognitive, language, and combined Bayley outcomes were positive but did not reach statistical significance. Total brain volume at discharge was not associated with neurodevelopmental outcomes in any domain. Cerebral growth rate was modestly correlated with the decline in head circumference percentile from birth to discharge. Conclusion: Longitudinal ultrasound-derived cerebral brain growth is associated with motor development at two years corrected age in VLBW infants, whereas single time-point brain volume measurements are not. Serial cranial ultrasound represents a feasible bedside approach to complement clinical risk assessment and may contribute to early neurodevelopmental risk stratification.