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 individual. 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
Vaginal atresia arises from a specific defect in the embryological development of the lower female reproductive tract. During normal female development, the paired Müllerian ducts give rise to the fallopian tubes, uterus, cervix, and upper vagina, while the urogenital sinus forms the lower vagina. The precise contributions of each structure to vaginal formation remain a subject of debate, with the most widely accepted model suggests that the Müllerian ducts contribute the upper two-thirds and the urogenital sinus the lower one-third. In vaginal atresia, the urogenital sinus fails to contribute to the caudal vaginal segment. The lower one-fifth to one-third of the vagina is replaced by approximately 2–3cm of fibrous tissue, above which the upper vagina, cervix, uterine corpus, and fallopian tubes typically remain well-differentiated. Normal vaginal development is complete by approximately 20 weeks of gestation. The molecular and genetic mechanisms underlying vaginal atresia have not been fully understood.
Related Disorders
Mayer–Rokitansky–Küster–Hauser syndrome Müllerian agenesis, also known as Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome, is a congenital disorder in females where the uterus and the upper two-thirds of the vagina are absent or underdeveloped. Affected individuals are genetically female, with 46,XX chromosomes, reflecting typical female genetic makeup. Kidney anomalies, such as renal agenesis, cysts, or ectopic kidneys, frequently accompany this disorder due to the close embryological development of the reproductive and urinary systems. Additionally, abnormal androgen production may also occur, resulting in hyperandrogenism and Müllerian aplasia.
This condition affects approximately 1 in every 4,000 to 5,000 females and is often diagnosed during adolescence when menstrual periods are absent, despite normal ovarian function and secondary sexual features development.
Bardet–Biedl syndrome Bardet–Biedl syndrome (BBS) is a ciliopathic human genetic disorder that can affect various parts of the body. Parts of the urogenital system where the effects of BBS are seen include: ectopic urethra, kidney failure, uterus duplex, hypogonadism, septate vagina, and hypoplasia of the fallopian tubes, uterus, ovaries. Some of the common characteristics associated with this syndrome include intellectual disorders, loss of vision, kidney problems, and obesity.
The mechanism that causes BBS remains unclear. Mutations in more than 20 genes can cause BBS, which is an inherited recessive condition. Some of the gene mutations that occur in BBS are listed below:
BBS1, BBS2, ARL6 (BBS3), BBS4, BBS5, MKKS (BBS6), BBS7, TTC8 (BBS8), BBS9, BBS10, TRIM32 (BBS11), BBS12, MKS1 (BBS13), CEP290 (BBS14), WDPCP (BBS15), SDCCAG8 (BBS16), LZTFL1 (BBS17), BBIP1 (BBS18), IFT27 (BBS19), IFT72 (BBS20), and C8ORF37(BBS21) Most genes associated with BBS encode proteins that are related structures called cilia and basal bodies.
Fraser syndrome Fraser syndrome is a rare autosomal recessive disorder that disrupts development before birth, characterised by cryptophthalmos, cutaneous syndactyly, and abnormalities of the urinary tract, most often renal agenesis. Genital malformations are common and account for its association with vaginal atresia. In affected females these may include vaginal atresia and, less commonly, hypoplasia or agenesis of the vagina and uterus.
McKusick–Kaufman syndrome McKusick–Kaufman syndrome typically presents with vaginal atresia and is often linked to other anomalies such as imperforate anus, congenital heart defects which can vary in severity and type, hydrometrocolpos (fluid buildup in the uterus and vaginal canal due to outflow obstruction), and polydactyly. Despite these issues, secondary sexual features like breast development and pubic hair typically still develop during puberty.
Mechanism The exact mechanism for vaginal atresia is not well known, as specific molecular mechanisms which lead to the closing or absence of the vagina are unclear. There are various pathways that may support or restrict regular vaginal development. Research has shown that changing factors may also include paracrine and autocrine signals and changes in the basis of developing organs. Specific patterns of genetic transmission have not been identified for this condition. Normal reproductive organ production requires timely coordination of the following systems: external genitalia, internal ductal system, and gonadal structure. The abnormal development of the vagina results in an incomplete unit (low, mid, high transverse septum), failure of epithelium degeneration (imperforate hymen), and vaginal atresia.
According to a number of medical professionals, timely coordination of interdependent systems is required for normal reproductive organ development in both males and females. The description of vaginal atresia mechanism can be explained in several steps of development of the uterovaginal canal per the information provided by these medical professionals. These interdependent systems are external genitalia, gonadal structures, and internal ductal system. 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. Though the Müllerian and urogenital sinuses play a huge role in the derivation of the vagina, it is unclear how much of a role each of these play normal vaginal development.
Diagnosis Vaginal atresia can sometimes be diagnosed by physical examination soon after birth. A child with vaginal atresia often has other congenital abnormalities and other tests such as X-ray and tests to evaluate the kidneys are done. Findings in adolescents may include abdominal pain, difficulty voiding, and backache, but most present with amenorrhea. Difficulties with sexual intercourse can suggest atresia. In the event that the condition is not caught shortly after birth, vaginal atresia becomes more evident when no menstrual cycle has occurred If vaginal atresia is suspected by the doctor, a blood test may also be requested for any of the previously mentioned signs and symptoms, a magnetic resonance imaging (MRI) test, or an ultrasound. A regular evaluation of children born with an imperforate anus or anorectal malformation should be paired with the assessment of the results from these tests. +Table: Summary of diagnostic methods used specifically for vaginal atresiaDiagnostic MethodPurpose in Diagnosing Vaginal AtresiaAdvantagesLimitationsPelvic ultrasoundUsed as an initial imaging tool to assess the presence of fluid build-up (hematocolpos) or cyclic pain or lack of periods (hematometra) caused by menstrual blockage in adolescents; can also evaluate uterine and renal anatomyNon-invasive, cost-effective, and widely available; useful for identifying fluid accumulation and guiding further testsMay not clearly visualize the extent or exact location of the atresia; less effective for detailed soft tissue anatomyMagnetic Resonance Imaging (MRI)Provides detailed multiplanar images of the vagina, uterus, ovaries, and renal system; distinguishes between partial and complete atresia; useful in surgical planningHigh-resolution, excellent soft tissue contrast; gold standard for anatomical mapping of congenital anomaliesExpensive; not always accessible in low-resource settingsDiagnostic laparoscopyUsed when non-invasive imaging is inconclusive; allows direct visualization of pelvic anatomy and detection of complications like endometriosis or hematosalpinxOffers visual confirmation of internal reproductive structures; useful for combined diagnosis and interventionInvasive; requires anesthesia and surgical setupHormonal testingHelps rule out endocrine causes of primary amenorrhea by evaluating levels of luteinizing hormone, follicle stimulating hormone, prolactin, estradiol, and thyroid hormonesUseful in narrowing differential diagnoses and confirming normal ovarian functionDoes not provide direct anatomical informationKaryotypingPerformed to confirm 46,XX chromosomal status and rule out conditions such as androgen insensitivity syndrome or Turner syndromeClarifies underlying genetic causes and differentiates from other causes of absent menstruationTime-consuming; not diagnostic of atresia on its ownClinical examinationPhysical inspection may reveal an absent or shortened vaginal canal, especially in neonates or adolescents with amenorrhea or failed tampon useQuick and accessible; can raise early suspicion of vaginal atresiaFindings may be subtle or missed without further imaging; can be distressing if not handled sensitively
Treatment