Vaginal atresia is a condition in which the vagina is abnormally closed or absent. The main causes can either be complete vaginal hypoplasia, or a vaginal obstruction, often caused by an imperforate hymen or, less commonly, a transverse vaginal septum. It results in uterovaginal outflow tract obstruction. This condition does not usually occur by itself within an individual, but coupled with other developmental disorders within the female. The disorders that are usually coupled with a female who has vaginal atresia are Mayer-Rokitansky-Küster-Hauser syndrome, Bardet-Biedl syndrome, or Fraser syndrome. One out of every 5,000 women have this abnormality. Symptoms and signs
Symptoms and signs in the newborn can be sepsis, abdominal mass, and respiratory distress. Other abdominopelvic or perineal congenital anomalies frequently prompt radiographic evaluation in the newborn, resulting in a diagnosis of coincident vaginal atresia. Symptoms for vaginal atresia include cyclical abdominal pain, the inability to start having menstrual cycles, a small pouch or dimple where a vaginal opening should be, and pelvic mass when the upper vagina becomes filled with menstrual blood. Signs and symptoms of vaginal atresia or vaginal agenesis can often go unnoticed in females until they reach the age of menstruation. Women may also experience some form of abdominal pain or cramping. Causes
The cause for vaginal atresia is unknown. Typically, the creation of the vaginal canal is completed within the fetus by the 20th week of gestation. Researchers believe in patients with vaginal atresia, tubes known as the Müllerian ducts do not develop correctly within the first 20 weeks of gestation/pregnancy.
The absence of androgens, Müllerian-inhibiting substance (MIS), and testes causes the continuous differentiation of the Müllerian ducts with reversion of the wolffian ducts in the female embryo. The Müllerian duct will then elongate to reach the urogenital sinus within 9 weeks of gestation; this forms the uterovaginal canal. By 15–26 weeks of gestation, cephalic growth of the sinovaginal bulb is completed. The vaginal plate is also formed from the fusion of vaginal cord with the sinovaginal bulb. The formation of the uterovaginal canal is thought to occur from the caudal to the cephalic portion, all while the urogenital sinus is used to create the epithelial lining. Development of the vagina is completed by the fifth month of gestation. While the mesenchyme that surrounds the structures transitions into musculature of the genital tract, the fallopian tubes are formed via the cephalic remnants of the Müllerian duct. This developmental process attributes to the process of how proper vaginal development takes place. Failure of the septum to regress between the fused Müllerian ducts results in a septate uterus. The incomplete fusion of the Müllerian ducts attributes to the formation of arcuate, bicornuate, or didelphid uteri.Females who have both Rokitansky-Mayer-Küster-Hauser syndrome and uterovaginal atresia are theorized to have a failing caudal development within the Müllerian ducts. Variations of transverse vaginal septum might be described by the malfunctions at the level of the vaginal plate.