Oxygen saturation and heart rate in healthy term and late preterm infants with delayed cord clamping

Abstract

Abstract: Blood oxygen in the fetus is substantially lower than in the newborn infant. In the minutes after birth, arterial oxygen saturation rises from around 50–60% to 90–95%. Initial respiratory efforts generate negative trans-thoracic pressures that drive liquid from the airways into the lung interstitium facilitating lung aeration, blood oxygenation, and pulmonary artery vasodilatation. Consequently, intra- (foramen ovale) and extra-cardiac (ductus arteriosus) shunting changes and the sequential circulation switches to a parallel pulmonary and systemic circulation. Delaying cord clamping preserves blood flow through the ascending vena cava, thus increasing right and left ventricular pre..