Title- Normative values of cerebral blood flow velocities in stable Very Low Birth Weight infants during first month of life.

Very Low Birth Weight (VLBW) infants undergo a dramatic change in hemodynamics during transition in the early neonatal period. Knowledge of postnatal age specific normative data on cerebral blood flow during first few weeks of life might be valuable and may help in early identification of abnormal adaptation. Besides this, cerebral blood flow changes can be detected before clinical decompensation of circulatory response occurs. However before attempting to interpret changes in acute diseased states, it is imperative to understand normal changes in cerebral blood flow in neonates. Longitudinal data on changing cerebral hemodynamics after birth are still lacking. There is a need to define gestation specific longitudinal data on cerebral blood flow indices in hemodynamically stable VLBW infants. We plan to conduct an observational study to determine normative values of cerebral blood flow velocities in anterior cerebral artery, middle cerebral artery and basilar artery in stable VLBW infants in the first month of life (at 2-8 hours, 24 hours, 3 days, 7 days, 14 days and 28 days or at the time of discharge).