 There is evidence, however, that the Bainbridge reflex does occur in humans, as in after delivery of an infant when a large volume (up to 800 mL) of uteroplacental blood is put back into the mother's circulation, resulting in tachycardia (citation needed).As venous return increases, the pressure in the superior and inferior vena cava increase.This results in an increase in the pressure of the right atrium, which stimulates the atrial stretch receptors (low pressure receptor zones).