Which vessel carries highest oxygenated blood in fetus, IVC or umbilical vein?

Which vessel carries highest oxygenated blood in fetus, IVC or umbilical vein?

In the fetus, the umbilical vein carries the highest concentration of oxygenated blood. This vein transports oxygenated blood from the placenta to the fetus, providing the developing fetus with the oxygen and nutrients necessary for growth and development.

After the oxygenated blood is delivered to the fetus via the umbilical vein, it enters the fetal circulation system. Some of this oxygenated blood is diverted away from the liver through the ductus venosus and directly into the inferior vena cava (IVC), where it mixes with the deoxygenated blood returning from the lower body. From the IVC, the mixed blood is then pumped into the right atrium of the heart and then circulated throughout the fetal body.

So, while the IVC carries blood from both the lower body and the umbilical vein, it is the umbilical vein that carries the highest concentration of oxygenated blood in the fetus.