Abstract
<b><i>Introduction:</i></b> Due to concerns of oxidative stress and injury, most clinicians currently use lower levels of fractional inspired oxygen (FiO<sub>2</sub>, 0.21–0.3) to initiate respiratory support for moderate to late preterm (MLPT, 32–36 weeks gestation) infants at birth. Whether this practice achieves recommended oxygen saturation (SpO<sub>2</sub>) targets is unknown. <b><i>Methods:</i></b> We aimed to determine SpO<sub>2</sub> trajectories of MLPT infants requiring respiratory support at birth. We conducted a prospective, opportunistic, observational study with consent waiver. Preductal SpO<sub>2</sub> readings were obtained during the first 10 min of life from infants between 32 and 36 weeks gestation requiring respiratory support in the delivery room. Primary outcome was reaching a minimum SpO<sub>2</sub> 80% at 5 min of life. The study was prospectively registered (ACTRN12620001252909). <b><i>Results:</i></b> A total of 76 eligible infants were recruited between February 2021 and March 2022 from 5 hospitals in Australia. Most (<i>n</i> = 58, 76%) had respiratory support initiated with FiO<sub>2</sub> 0.21 (range 0.21–1.0) using CPAP (92%). Median SpO<sub>2</sub> at 5 min was 81% (interquartile range [IQR] 67–90) and 93% (IQR 86–96) at 10 min. At 5 min, 18/43 (42%) infants had SpO<sub>2</sub> below 80% and only 8/43 (19%) reached SpO<sub>2</sub> 80–85%. <b><i>Conclusions:</i></b> Many MLPT infants requiring respiratory support do not achieve recommended SpO<sub>2</sub> targets. In very preterm infants, SpO<sub>2</sub> <80% at 5 min of life increases risk of death, intraventricular haemorrhage, and neurodevelopmental impairment. The implications on this practice on the health outcomes of MLPT infants are unclear and require further research.