Several small studies on FiO2 for resuscitating preterm infants have been performed. Wang et al. compared the use of initiating the resuscitation of preterm infants with either room air (n = 18) or 100% oxygen (n = 23) [3]. All infants in the room air group required an increase of the FiO2 to achieve the targeted oxygen saturation (SpO2), and the authors recommended that room air should not be used for resuscitating preterm infants. Escrig et al. compared initiating resuscitation of preterm infants with a gestational age (GA) ≤ 28 weeks with either 30% or 90% oxygen [4]. In this study, the FiO2 in the low-oxygen group (n = 19) was increased stepwise to 45%, and the FiO2 in the high-oxygen group (n = 23) was reduced to 45% to reach the target SpO2. In a similar study by Vento et al., resuscitation with 30% oxygen (n = 37) resulted in decreased oxidative stress markers and a decreased risk of bronchopulmonary dysplasia (BPD) compared to starting resuscitation with 90% (n = 41) [5]. Also in this study, FiO2 in both groups was increased stepwise in the low-oxygen group and decreased in the high-oxygen group, reaching 55% at 5 min in both groups.