Abstract
Fetal to neonatal transition is characterized by an abrupt increase in the arterial partial pressure of oxygen and oxygen delivery to the tissue both causing a physiologic pro-oxidant status. Under normal circumstances arterial oxygen saturation measured by preductal pulse oximetry in term babies does not reach consistent values (85–90%) until four to five minutes after cord clamping, and 7 to 10 minutes in preterm infants. Of note, the time needed to stabilize saturation inversely correlates with gestational age. Oxygen in excess causes oxidative stress and inflammation in preterm infants. In order to avoid these negative consequences the inspiratory fraction of oxygen should be titrated until achievement of stable and safe oxygen saturation. Remarkably, the availability of an oxygen saturation nomogram could be of great help for the care givers. Supplementing the newborn with high inspiratory fractions of oxygen pursuing to rapidly achieve high oxygen saturation should be avoided. Instead, a proposal consisting in initiating resuscitation with lower oxygen inspiratory fractions and titrating according to targeted saturations is proposed. Multicenter international prospective randomized clinical trials powered to evaluate oxygen administration in the first minutes of life and neurodevelopment at two years are being launched at present and hopefully will clarify many of our doubts.