What factor is responsible for closure of the foramen ovale?

Question

Quizplus · Accepted Answer

The increased fetal blood flow that results from the drop in PVR increases pulmonary venous blood return and, therefore, increases the left atrial pressure. At the same time, the RA pressure decreases when the umbilical cord is ligated and no longer provides placental blood flow to the IVC. The result of the higher LA pressures and the lower RA pressures is the closure of the foramen ovale.

What Factor Is Responsible for Closure of the Foramen Ovale