Transverse Septum
A transverse septum can form during embryogenesis when the mullerian ducts fuse improperly to the urogenital sinus. A complete transverse will block menstrual flow and is a cause of primary amenorrhea. The accumulation of menstrual debris behind the septum is termed cryptomenorrhea. Some transverse septa are incomplete and may lead to dyspareunia or obstruction in labor. A surgical incision will relieve the situation.
Read more about this topic: Vaginal Septum