Transcranial Doppler Evaluation of Cerebral Hemodynamics in Term and Preterm Chinese Neonates aged <7 days: a retrospective cohort study

Objective: To establish normative TCD-derived cerebral blood flow values in term and preterm neonates and to assess differences between groups and their associations with gestational age and anthropometric parameters. Methods: A retrospective cohort study was performed on 46 neurologically and hemodynamically stable neonates admitted to the Neonatal ward of Zhongshan City People’s Hospital between April and August 2025. TCD examinations of the anterior (ACA), middle (MCA) and posterior cerebral arteries (PCA) were completed within the first postnatal week in both term and preterm infants. Cerebral hemodynamic parameters-peak systolic velocity (Vs), end-diastolic velocity (Vd), mean velocity (Vm), pulsatility index (PI) and resistance index (RI)-were compared between groups and correlated with gestational age, birth weight and occipito-frontal head circumference. Results: Hemodynamic findings showed that compared with term neonates, preterm neonates showed significantly lower blood flow velocities in the left MCA. In contrast, preterm infants exhibited significantly higher vascular resistance in multiple cerebral arteries, with the increase being more pronounced in the right hemisphere. Standardized linear regression analyses showed that GA and BW were positively associated with vascular velocity in both ACA and MCA. Models for left MCA flow velocities demonstrated moderate explanatory power (R² values ranging from 0.25 to 0.34). Conclusion: Term and preterm neonates exhibited distinct hemodynamic profiles on TCD within the first seven days of life. The most pronounced difference between the two groups was observed in the MCA. BW demonstrated the strongest association with these hemodynamic differences.