The exact frequency has not been documented because PAVFs have not been carefully studied. In adults PAVF seems to occur more frequently in females than in males by almost a 2:1 ratio; among newborns, males are more frequently affected.

The exact cause of PAVF has not been demonstrated. One theory suggests that a defect resulting in dilation of thin capillary sacs occurs in the terminal arterial loop. A different theory suggests the cause may be an incomplete resorption of the vascular septa separating the arterial and venous plexus that would usually anastomose during fetal development. Still another theory points to development of small PAVFs resulting from failure of capillary development during fetal growth.