There are many parameters that influence the haemodynamic situation, including heart rate, stroke volume, cardiac output, and blood pressure. As transition of the newborn is a very dynamic situation, studies have to follow a timeline in order to cover all changes over time. Furthermore, it has been shown that the main driving force for establishing lung perfusion is aeration of the lungs. A further important aspect, it has been shown in animal experiments that clamping the cord results inmay have significant impact on the haemodynamic situation, as by clamping the cord there is a loss of blood volume of the placenta resulting in a significant drop in venous return to the right atrium. A quick switch of the shunt flow direction via the open ductus arteriosus from right-to-left to left-to-right is able to compensate for that. If there is no left-to-right shunt via the duct in this situation this may impair blood flow to organs, as for instance the brain (Urlesberger et al, Neonatology 2013). All these data have resulted in a more profound discussion of the possible benefits of delayed cord clamping.

At the moment we have data to different aspects of the haemodynamic situation in human studies, including ductal shunting (van Vonderen et al, Arch Dis Child Fetal Neonatal Ed 2014) behaviour of stroke volume and cardiac output (van Vonderen et al, Pediatr Res 2014, Noori et al J Pediatr 2013). The presentation will give an overview of all these publications, adding data that are about to be published.