Objective
To systematically review the use of NIRS measured cerebral oxygenation and analyse these parameters during the immediate postnatal period.

Data Sources
EMBASE, MEDLINE, and Maternity and Infant Care databases using keywords: “Infants,” “NIRS,” and “Cerebral oxygenation.”

Study selection
Inclusion criteria were clinical trials and observational studies measuring cerebral oxygenation up to 15 min of life. Exclusion criteria were non-human studies, non-English articles and case reports.

Data extraction
Two authors independently performed study selection, data extraction, and risk of bias assessment. Cerebral regional tissue Oxygenation (CrSO2) and cerebral fractional tissue oxygenation extraction (cFTOE) values were extracted.

Results
Fifty nine studies, out of 4067 were included in the qualitative analysis. Studies included aimed to establish oxygenation reference ranges, assess the impact of delivery mode, cord clamping, and delivery room interventions on cerebral oxygenation, and evaluated its role in predicting long-term neurodevelopmental outcomes. Most studies focused on term neonates experiencing normal neonatal transitions. Aggregate mean values for CrSO2 and cFTOE in the first 15 min of life were calculated, showing that a steady state is achieved by 10–15 min of life. ANOVA demonstrated no significant differences between preterm and term infants in CrSO2 (p = 0.54) and cFTOE (p = 0.50).

Conclusions
NIRS measurement of CrSO2 is feasible and can be used alongside other clinical tools to inform delivery room management. There were no significant differences in CrSO2 or cFTOE between term and preterm infants although most studies focussed on late preterm infants. Future research is therefore required for extremely preterm infants, those requiring ventilatory management, or those with congenital anomalies.