Abstract
Optimal oxygenation requires the delivery of oxygen to meet tissue metabolic demands while minimizing hypoxic pulmonary vasoconstriction and oxygen toxicity. Oxygen saturation by pulse oximetry (SpO(2)) is a continuous, non-invasive method for monitoring oxygenation. The optimal SpO(2) target varies during pregnancy and neonatal period. Maternal SpO(2) should ideally be ≥95 % to ensure adequate fetal oxygenation. Term neonates can be resuscitated with an initial oxygen concentration of 21 %, while moderately preterm infants require 21-30 %. Extremely preterm infants may need higher FiO(2), followed by titration to desired SpO(2) targets. During the NICU course, extremely preterm infants managed with an 85-89 % SpO(2) target compared to 90-94 % are associated with a reduced incidence of severe retinopathy of prematurity (ROP) requiring treatment, but with higher mortality. During the later stages of ROP progression, studies suggest that higher SpO(2) targets may help limit progression. A target SpO(2) of 90-95 % is generally reasonable for term infants with respiratory disease or pulmonary hypertension, with few exceptions such as severe acidosis, therapeutic hypothermia, and possibly dark skin pigmentation, where 93-98 % may be preferred. Infants with cyanotic heart disease and single-ventricle physiology have lower SpO(2) targets to avoid pulmonary over-circulation. In low- and middle-income countries (LMICs), the scarcity of oxygen blenders and continuous monitoring may pose a challenge, increasing the risks of both hypoxia and hyperoxia, which can lead to mortality and ROP, respectively. Strategies to mitigate hyperoxia among preterm infants in LMICs are urgently needed to reduce the incidence of ROP.