# Sonographic Brain Volume Growth Trajectories in VLBW and Clinical Determinants—Data from the NeoNEVS Project

## TL;DR

This study shows that serial cranial ultrasound can track brain growth in very low birth weight infants, with prolonged ventilation linked to slower brain growth.

## Contribution

The study introduces a feasible bedside ultrasound method for longitudinal brain volume monitoring in VLBW infants.

## Key findings

- Median cerebral volume increased from 164 cm³ to 275 cm³ during NICU stay.
- Longer invasive ventilation was associated with reduced cerebral growth (p < 0.01).

## Abstract

What are the main findings?
Serial bedside cranial ultrasound with an ellipsoid model provides reproducible longitudinal estimates of total brain volume growth in VLBW infants during NICU stay.Longer duration of invasive mechanical ventilation is associated with slower ultrasound-derived brain volume growth.

Serial bedside cranial ultrasound with an ellipsoid model provides reproducible longitudinal estimates of total brain volume growth in VLBW infants during NICU stay.

Longer duration of invasive mechanical ventilation is associated with slower ultrasound-derived brain volume growth.

What are the implications of the main findings?
Internally derived percentile trajectories can help contextualize an individual infant’s brain growth pattern over time.This feasible bedside approach may support routine monitoring and hypothesis-driven risk stratification when interpreted alongside standard clinical and anthropometric data.

Internally derived percentile trajectories can help contextualize an individual infant’s brain growth pattern over time.

This feasible bedside approach may support routine monitoring and hypothesis-driven risk stratification when interpreted alongside standard clinical and anthropometric data.

Background: Very Low Birth Weight preterm infants are at elevated risk for disrupted brain growth and later neurodevelopmental impairment. Bedside-accessible tools for monitoring cerebral development remain limited. Methods: In this retrospective pilot cohort study, 153 Very Low Birth Weight infants (<32 weeks gestational age and/or <1500 g) from two Level III Neonatal Intensive Care Units underwent serial cranial ultrasound assessments. Total brain volume was estimated using an ellipsoid formula derived from standardized imaging planes. Growth trajectories were analysed via linear mixed-effects modelling. Associations with clinical predictors—including invasive ventilation, sepsis, and somatic growth—were evaluated. Results: A total of 976 brain volume measurements were collected. Median cerebral volume increased from 164 cm3 to 275 cm3 across the hospital stay, corresponding to a median growth rate of 2.3 cm3/day (95% CI: 1.5–3.1). Duration of invasive mechanical ventilation was associated with reduced cerebral growth (p < 0.01, R2 = 0.26). Cerebral volume growth showed a weak but statistically significant correlation with head circumference percentile progression (p < 0.05, ρ = 0.16). Conclusions: Sonographic brain volumetry is a feasible and non-invasive method for tracking cerebral development in Very Low Birth Weight infants. These findings confirm significant associations between cerebral growth and head growth and identify prolonged invasive ventilation as a risk factor for impaired cerebral development.