The umbilical arterial catheter should pass through the umbilicus, travel inferiorly through the umbilical artery into the common iliac artery and then into the aorta. The tip of the umbilical arterial catheter should be away from major vessels so that it does not block the vessel or instill a high-concentration solution directly into an organ-feeding vessel, such as the renal artery. It should be placed either in a high position at the T6 to T10 level or in a low position at the L3 to L5 level. An umbilical venous catheter can be distinguished from an umbilical arterial catheter as the umbilical venous catheter travels cranially in the umbilical vein while the umbilical arterial catheter travels caudally in an umbilical artery to reach a common iliac vessel.