Numerous changes occur in the region of the postcardinal veins due to the development of new structures. The development of the lower limbs leads to the formation of sacrocardinal veins, from which the common iliac vein and the prerenal segment of the inferior vena cava develop. The subcardinal veins arise along with the development of the mesonephros, and are the origin of the renal segment of the inferior vena cava.
The heart is not shown in diagrams illustrating the development of the inferior vena cava.