This is the blood circulation in a fetus. It is distinct from newborn and adult circulation in the following aspects: in fetal circulation, the cardiac output not only has to perfuse the body, but also the placenta (55% of output goes to the placenta). the umbilical cord connects the placenta to the fetus, blood from the fetal heart enters the placenta via the umbilical artery the umbilical vein contains oxygenated blood as versus the artery in newborn or adults containing oxygenated blood. there are two umbilical arteries and one umbilical vein. the pressure of the right heart chambers in the fetal circulation is higher than that of the left chambers, as a result, blood from right atrium passes through the foremen ovale to the left atrium, and blood from pulmonary artery passes through the ductus arteriosus to the aorta.