No abstract

Background: Transition from fetal to extra uterine circulation is a poorly understood process in terms of cerebral hemodynamics. Postnatal cerebral circulation and autoregulation is affected by the degree of prematurity and fetal hypoxia. Currently, the data on changes in postnatal cerebral blood flow indices in preterm and SGA neonates is limited. Objective: To investigate the differences between cerebral hemodynamics between preterm (28 0/6- 34 6/7) small for gestational age (SGA) and appropriate for gestational age (AGA) neonates. Methodology: In this prospective cohort study done in a tertiary care centre of South India in the year 2020-2021, we compared cerebral function parameters as assessed by doppler sonography between hemodynamically stable SGA (n = 57) and AGA neonates (n = 91) admitted to the NICU during the first 72 hours. Results: Preterm SGA neonates have significantly lower pulsatility index (PI) and resistive index (RI) in middle cerebral artery on day 2 and day 3. On day 2, the median (IQR) PI was 1.05 (0.91-1.98) vs 1.26 (1.10-1.39), p=0.002 and mean ± SD RI of 0.67 ± 0.09 vs 0.71 ± 0.08, p=0.01 and on day 3 median (IQR) PI was 1.12 (1.01-1.32) vs 1.28 (1.10-1.51), p=0.05 and mean ± SD RI of 0.68 ± 0.08 vs 0.72 ± 0.10 (p = 0.01) in SGA and AGA neonates respectively. Conclusion: SGA neonates have significantly lower indices of cerebral perfusion as seen by low PI and RI in MCA (middle cerebral artery) as compared to their AGA counterparts.