The theorized function of the Hyl anastomosis is equalization of which of the following?

The Hyl anastomosis is a common connection between the umbilical aeries near the cord inseion in most human placentas. It has been speculated that it equalizes the blood pressure between the territories supplied by the umbilical aeries. When placental territories of one aery impose increased resistance to fetal blood flow, the Hyl anastomosis redistributes the blood flow into the second aery to reduce the large pressure gradients that are developed in the affected aery. The Hyl anastomosis plays the role of either a safety valve or a pressure stabilizer between the umbilical aeries at the placental inseion.