Our study results suggest that breast milk was better tolerated than formula, requiring lower energy expenditure and lower cerebro-splanchnic haemodynamic redistribution. The findings could prompt investigations using NIRS as a promising noninvasive tool for cerebral and splanchnic longitudinal monitoring during neonatal feeding.

Our results, showing impaired oximetry and function of CNS in LPT, offer additional support to NIRS parameters as a useful tool for longitudinal CNS monitoring of very preterm infants becoming LPT. Future studies correlating NIRS variables and long-term neurological outcome in LPT are needed to elucidate the concept of dynamic brain damage pathogenesis.

Aim: Near-infrared spectroscopy (NIRS) has been proposed to provide reliable information concerning brain oximetry and tissue activation level in the perinatal period. We aimed to investigate whether NIRS brain patterns in healthy preterm (PT) and term (T) infants were gender-and gestational age (GA)-dependent. Methods:We conducted an observational study in 74 newborns, from consecutive singleton pregnancies, of whom 37 were born at term (male: n = 19 female: n = 18) and 37 (male: n = 18 female: n = 19) were PT. Cerebral oximetry (crSO 2 ) and fractional tissue oxygen extraction (cFTOE), were recorded on the 5th day from birth.Results: crSO 2 was significantly higher and cFTOE lower (p < 0.001, for both) in the PT female than male group. At term, crSO 2 was significantly higher and cFTOE lower (p < 0.001, for both) in males. crSO 2 (male: R = 0.84, p < 0.001; female: R = 0.74, p < 0.001) and cFTOE (male: R = 0.72, p < 0.001; female: R = 0.72, p < 0.001) in male and female groups correlated positively with GA at recording. Conclusion: Different brain oximetry between males and females in PT a T infants, maysuggest that in the perinatal period brain development is gender-and time-dependent. Data support the use of NIRS as a feasible tool for non-invasive cerebral monitoring.Brain development is gender and gestational agedependent. Brain development in the late preterm period is more precocious in females than in males. Results offer further support to the concept of the higher preterm male infants vulnerability as confirmed by higher incidences of prematurity and of brain and multi-organ failure.1036

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