Cerebral Resistive Indices and Intraventricular Hemorrhage in Premature Neonates <29 weeks’ gestation: A Pilot Prospective Cohort Study

Background: In extremely preterm newborns, intraventricular hemorrhage (IVH) greatly influences neurodevelopmental outcomes. Preterm newborns who later develop IVH might have altered cerebral blood flow (CBF) as measured by resistive index (RI) on Doppler ultrasound. Knowledge regarding RI in extremely premature infants remains limited. Objective: This pilot prospective cohort study aimed to evaluate the association between early cerebral RI (within the first 36 hours of life) and the occurrence of IVH in preterm infants born at < 29 weeks' gestation. Methods: Prospective cohort study in which cranial Doppler was performed in preterm infants < 29 weeks at < 36 hours of age and between 5–7 days of age. CBF velocities and RI were measured. Clinical and demographic factors were also assessed. Results: Of the 30 enrolled infants, 27% developed an IVH. RI measured at < 36 hours of life for the neonates with IVH was significant higher compared to those who did not have IVH (0.70(± 0.04) vs 0.65(± 0.05); p = 0.02). Multiple regression showed RI amongst babies with IVH was higher by 0.05, when controlled for other clinical variables (p = 0.01). These differences were not statistically significant when measured at 5–7 days. RI had no significant correlation with antenatal steroid use, delayed cord clamping, or presence of hemodynamically significant patent ductus arteriosus. Conclusion: Higher cerebral RI measured within the first 36 hours of life was associated with IVH in this pilot study. These early results draw attention to the requirement for bigger, sufficiently powered research to assess RI as a possible early sign for IVH risk stratification in very preterm newborns.