The transverse vaginal septum is caused by the evolution of the vaginal plate from the urogenital sinus, the vaginal bulb, during the embryonic period by proliferation and growth towards the cephalic end, which is obstructed during the luminalization from the bottom to the top, and the transverse vaginal septum is not penetrated or not fully luminalized. It often occurs at the junction of the upper and middle 1/3 of the vagina, but can also occur anywhere in the vagina up to the tip of the vagina, near the cervix. It may be due to a lack of penetration of the caudal end of the paramedian tubules on both sides where they meet the urogenital sinuses. Complete transverse septum is rare and may result in vaginal atresia; it usually has small holes in the center or lateral aspect of the septum, which vary in size and interfere with the drainage of vaginal fluid and menstrual blood. Transverse vaginal septum is the result of a vaginal plate that evolves during the embryonic period from the urogenital sinus, the vaginal bulb, that proliferates and grows toward the cephalic end and is obstructed during the luminalization from the bottom up, resulting in an incomplete or incomplete luminalization of the vaginal septum. The transverse septum may occur in the higher part of the vagina and may be partially atretic, which may not affect sexual life and may allow conception, but may interfere with delivery of the fetus during labor and delivery, so a transverse septotomy should be performed during delivery. Whether the vaginal septum develops clinical symptoms depends firstly on the presence or absence of a small hole in the septum and secondly on the height of its position. The thickness also varies, with some vaginal septum being very thin and paper-like and others thicker. Most of them have a small hole in the center of the septum, sometimes only through a fine probe, and the menstrual blood can flow out without symptoms until after marriage, when it is discovered due to difficulty in sexual intercourse or obstruction of the fetal head during delivery. If there is no hole in the septum, symptoms will occur once menstrual blood is trapped after menarche. When examining the vaginal septum, the first thing to look for is the presence of a small hole in the septum (often in the central part), and if there is a hole, a probe can be inserted into the septum to check the width and depth of the vagina above the hole to make a diagnosis. Incomplete vaginal septum is common and is often ignored because it has no clinical symptoms.