Figure 2.

In 1994, theory of “Levels of Support” was proposed by Delancey, level 1 (A) is the upper supporting structure (main ligament-uterine low ligament complex); level 2 (B) is the lateral supporting structure (levator ani muscle group and bladder, rectovaginal fascia), level 3 (C) is the distal supporting structure (perineum and sphincter).