Internal Cerebral Vein Doppler Velocities Reflect Maturational Changes and Hemorrhage Risk in Preterm Infants

ABSTRACT BACKGROUND AND PURPOSE: Preterm infants are at risk of brain injury due to immature cerebral autoregulation. However, reliable assessment of cerebral perfusion remains difficult: advanced imaging is rarely feasible at the bedside, and surrogate markers such as blood pressure or oxygen saturation correlate poorly with actual cerebral blood flow. This study aimed to evaluate the velocity and waveform characteristics in the internal cerebral veins (ICV) of preterm infants born before 32 weeks and to explore the relationship between these velocities, clinical parameters, and term-equivalent MRI. MATERIALS AND METHODS: Prospectively, a cohort of 47 preterm infants (postmenstrual age 28.9 ± 2.2 weeks, birth weight 1304 ± 386 g) admitted to the NICU at University Hospital Brussels was studied. ICV velocities were measured at multiple time points using Doppler ultrasound as a non-invasive marker of cerebral hemodynamics. Mixed model analysis compared ICV velocities with clinical and term-equivalent MRI results. RESULTS: ICV velocity/weight at the time of scan was significantly associated with postmenstrual age (PMA, p<0.001), postnatal age (PA), and PA squared (both p<0.001), intraventricular hemorrhage (IVH) during admission (p=0.003), and the interaction between gestational age and IVH (p=0.005), reflecting developmental changes in cerebral circulation. IVH was observed in 5 infants. ICV velocity/weight was 1 cm/s/kg higher with IVH at 25 weeks’ GA, decreasing to -0.1 cm/s/kg with IVH at 29 weeks’ GA. Although the number of IVH cases was limited, these findings suggest that ICV velocity monitoring may provide useful information regarding IVH risk. CONCLUSIONS: ICV velocity in preterm infants reflects cerebral maturation. Infants developing IVH showed significantly higher venous velocities, corrected for body weight. Despite limited case numbers, these findings indicate that ICV velocity monitoring could serve as an early marker of hemorrhage risk. Larger studies are needed to confirm its predictive value and explore potential neuroprotective strategies. ABBREVIATIONS: IVH = Intraventricular Hemorrhage; ICV = Internal Cerebral Vein; NIRS = near-infrared spectroscopy; cUS = Cranial Ultrasound; PMA = postmenstrual age.