Background and aims Low birth weight in conjuction with the immature autoregulation mechanisms noted in preterm neonates may influence brain perfusion and consequently the neurodevelopmental outcome.

The aim of this study was to assess the potential variations in brain oxygenation and perfusion in SGA neonates of different gestational age during the first postnatal week with the use of Near Infrared Spectroscopy (NIRS).

Patients/methods SGA neonates born at 28–32 weeks and 32⁺¹–36 weeks respectively consisted the two study groups. Three measurements of forty minutes each were performed with NIRO-200 NX instrument in the first, third and seventh day of life. Tissue oxygenation index (TOI), fraction tissue oxygen extraction (FTOE) and tissue haemoglobin index (THI) were the recorded parameters.

Results 38 neonates were prospectively enrolled; 12 were born at 28–32 weeks gestation and 26 at 32⁺¹–36 weeks. Mean birth weight and head circumference were 1.062 ± 265 vs 1.656 ± 401 and 26.0 ± 2.5 vs 30.4 ± 1.8 respectively in the study populations. Haemoglobin in the first day didn’t show any significant difference between the two subgroups (16.4 vs 17.8). NIRS monitoring found higher FTOE at the right side in more preterm SGA neonates (p = 0.018) in the first postnatal day. All the other parameters were similar in the two groups.

Conclusion It seems there aren’t significant differences in cerebral oxygenation and perfusion between SGA neonates of different gestational age during the first postnatal week.