Five-Minute Oxygen Saturation and Delivery Room Oxygen Requirements as Early Markers of Illness Severity in Preterm Infants ≤32 Weeks of Gestation: A Single-Centre Retrospective Cohort Study

Background and objectives: Optimal oxygen administration during delivery room resuscitation remains a major challenge in very preterm infants. While both hypoxemia and excessive oxygen exposure have been associated with adverse outcomes, the prognostic value of early oxygenation parameters remains unclear. This study aimed to evaluate the association between preductal SpO2 at 5 min of life and early respiratory and neurological outcomes in preterm infants born at or below 32 weeks of gestation. Materialsandmethods: This retrospective single-centre study included 31 preterm infants born at ≤32 weeks of gestation, identified from 34 consecutive eligible births. Demographic, delivery room, respiratory, laboratory, and neuroimaging data were collected from medical records. The primary outcome was intraventricular hemorrhage (IVH), graded by the Papile classification, during the first week of life. Secondary outcomes included respiratory support requirements, surfactant administration, and capillary blood gas parameters at two hours of life. Associations were evaluated using Spearman rank correlation; because SpO2@5 and delivery room FiO2 were strongly related to gestational age, partial correlations controlling for gestational age were additionally performed, together with a group comparison for IVH. Exact two-sided p values are reported. Results: The median gestational age was 28 weeks + 4 days (range: 22 weeks + 1 day to 31 weeks + 5 days), and the median birth weight was 1120 g. IVH of any grade occurred in 20 infants (64.5%), including severe (grade III–IV) IVH in 10 (32.3%). Median delivery room FiO2 was 35% (IQR 30–50%), and median SpO2 at 5 min of life was 83% (IQR 75–90%). Lower SpO2 at 5 min of life was associated with an increased number of surfactant doses (rs = −0.46, p = 0.010), lower capillary pH at two hours of life (rs = 0.39, p = 0.032), and a higher grade of IVH (rs = −0.39, p = 0.030); median SpO2@5 was 80% in infants with IVH versus 90% in those without (p = 0.057). Higher delivery room FiO2 was associated with increased use of DuoPAP (rs = 0.36, p = 0.045), mechanical ventilation (rs = 0.41, p = 0.021), and surfactant administration (rs = 0.56, p < 0.001), as well as lower pH (rs = −0.55, p = 0.002) and higher lactate levels (rs = 0.37, p = 0.044) at two hours of life. Because SpO2@5 and FiO2 were both strongly correlated with gestational age (rs = 0.54 and −0.76, respectively), all associations were re-examined controlling for gestational age. The associations of SpO2@5 with IVH grade (partial rs = −0.22, p = 0.247), surfactant doses (partial rs = −0.08, p = 0.678) and 2 h pH (partial rs = 0.19, p = 0.335) were attenuated and no longer significant, as were those of FiO2 with mechanical ventilation (partial rs = −0.04, p = 0.817) and surfactant doses (partial rs = −0.01, p = 0.945); only the association between FiO2 and 2 h pH persisted (partial rs = −0.37, p = 0.048). Conclusions: In preterm infants born at or below 32 weeks of gestation, lower SpO2 at 5 min and higher delivery room oxygen requirements were associated with less favorable respiratory and metabolic outcomes, as well as with IVH. However, apart from the association between FiO2 and 2 h pH, none of these associations remained statistically significant after adjustment for gestational age, and these findings, from a small and heterogeneous single-centre cohort, should be considered hypothesis-generating. Early oxygenation parameters are best viewed as simple bedside markers of cardiopulmonary adaptation and overall illness severity in very preterm infants, rather than as independent predictors of clinical outcomes. Further prospective studies are needed to confirm these associations and define clinically relevant threshold values.