*2.3. Near-Infrared Spectroscopy*

For cerebral NIRS measurements, the sensor was attached to the neonates' right forehead, and for peripheral NIRS measurements, the sensor was placed on the right forearm by a member of the research team. The sensors were fixed with a gauze bandage. crSO2/cTOI and prSO2 were measured continuously during the first 15 min after birth. crSO2/cTOI was measured either with the INVOS 5100C device (Somanetics Corporation, Troy, Michigan, USA) or the NIRO 200-NX tissue oxygenation monitor (Hamamatsu Photonics, Hamamatsu-city, Japan). prSO2 was measured with the INVOS 5100C device. The peripheral fractional oxygen extraction (pFTOE) was calculated as follows: pFTOE = [(SpO2 − prSO2)/SpO2].
