Delayed umbilical cord clamping and fraction of inspired oxygen in preterm infants: implications for postnatal...

The transition to extrauterine life involves profound respiratory and hemodynamic changes that enable the shift from transplacental to pulmonary gas exchange and the conversion of fetal circulation to neonatal circulation. In recent years, important modifications have been introduced in delivery room stabilization strategies, particularly regarding umbilical cord management and the initial fraction of inspired oxygen (FiO₂) in preterm infants. The aim of this review is to analyze the available evidence on delayed umbilical cord clamping, ventilation with an intact umbilical cord, and initial oxygen strategies during postnatal stabilization. We performed a narrative review of the recent scientific literature, including experimental studies, clinical trials, and meta-analyses evaluating the impact of these interventions in term and preterm newborns during early neonatal transition. Delayed cord clamping allows additional placental transfusion, increasing the circulating blood volume, improving ventricular preload, and promoting a more stable cardiovascular transition. These effects are associated with earlier stabilization of heart rate and oxygen saturation, as well as reduced supplemental oxygen requirements. Ventilation with an intact umbilical cord allows initiation of respiration while maintaining placental hemodynamic support, facilitating a more gradual cardiorespiratory transition. In addition, recent evidence suggests that initial FiO₂ levels above 0.30 may facilitate achieving the target oxygen saturation in the first minutes of life, particularly in extremely preterm infants.