Oxygen during Neonatal Resuscitation: Too Much versus Too Little, Does It Matter?

Background: Oxygen has been a key component of neonatal resuscitation for nearly two centuries. Based on clinical trials that demonstrated worse outcomes when neonatal resuscitation was initiated with 100% oxygen, there was a change in approach to using 21% oxygen at the initiation of ventilation for newborns at birth. However, for extremely preterm newborns, lower oxygen levels lead to early hypoxia and bradycardia, leading to higher rates of severe intraventricular hemorrhage and death. The balance between hyperoxia and hypoxia-related injury needs further refinement and may not be generalizable to all gestations and birth conditions. Summary: This article reviews the current evidence on oxygen use during delayed cord clamping, during resuscitation of term and preterm neonates, during chest compressions, after return of spontaneous circulation and in the post-resuscitation phase, and the impact of hyperoxia. Key Messages: Supplemental oxygen during neonatal resuscitation is actively being investigated by researchers worldwide to fill the knowledge gap to avoid hypoxia and hyperoxia while improving neonatal outcomes. Until further evidence emerges, we recommend starting resuscitation in the delivery room of very-low-birth-weight infants with an FiO₂ of 0.3-1, probably in the lower part of this scale, and titrating up by 10-20% every 30 s to achieve the target SpO₂ for age. An SpO₂ of 80-85% should be targeted by 5 min after birth.