What is Imperforate Hymen?
The hymen is a thin layer of skin found at the entrance of the vagina. Sometimes, this skin does not naturally open during a baby’s development – this is known as an imperforate hymen. An imperforate hymen can cause problems in the female reproductive and urinary system. It is a rare cause of a condition known as primary amenorrhea, which refers to never having a menstrual period. Babies with an imperforate hymen may develop a condition called mucocele, or a buildup of mucus, due to the influence of the mother’s naturally occurring estrogen in the body.
Many girls and women with an imperforate hymen may not show any symptoms until their first menstrual period starts. At this point, they may experience recurring abdominal pain and a lack of menstruation or amenorrhea. When a female is menstruating, the menstrual blood can accumulate in the vagina or womb, which can lead to the formation of a pelvic mass. This is a lump in the pelvic area, recognized during a physical exam as a blue, bulging mass in the area between the hips (perineal area). This lump can block the urinary system, leading to problems like difficulty in passing urine, swelling of the kidneys due to backflow of urine (hydronephrosis), or sudden kidney damage.
Doctors may recommend a procedure to open the hymen, called a hymenectomy, at puberty unless the child has urgent complications due to the pelvic mass. In such cases, immediate surgery might be necessary to avoid kidney damage, treat an infection, or prevent future fertility issues. The surgery aims to prevent the hymen from becoming imperforate again. Doctors who specialize in children’s health, women’s health, and children’s urinary health often encounter patients with an imperforate hymen. A combined approach from these specialists to assess and treat an imperforate hymen is usually the best option for the patient.
What Causes Imperforate Hymen?
During the development of the urinary and reproductive system, a part called the ‘cloaca’ gets divided into the ‘urogenital sinus’ (which forms the urinary and genital tracts) and the ‘anal canal’ (which forms the anus).
Two main duct systems play a key role in the formation of specific structures in male and female genital and urinary tracts: the Wolffian ducts and the Müllerian ducts. The Wolffian ducts develop in the paired of urogenital ridges (areas that form the urinary and reproductive organs), and help in the formation of structures called mesonephric tubules.
Moreover, the Wolffian ducts trigger the development of the Müllerian ducts from the covering of the paired urogenital ridges. The Müllerian ducts use the Wolffian ducts as guides and grow in the same direction. The close relationship of the Müllerian and Wolffian ducts can explain the frequent urinary tract issues in women who also have Müllerian problems.
These Müllerian ducts fuse together to form the uterovaginal canal – which later develops into the uterus, cervix, and the upper two-thirds of the vagina. The lower part of the vagina originates from the urogenital sinus.
The hymen, a portion of the female reproductive system, is thought to have originated from the urogenital sinus too. Its exact origin is a topic of debate among scientists. It is believed that the hymen usually creates an opening at about 22 weeks of pregnancy. In some cases, the hymen may not create this opening in line with the rest of the vagina when the sinovaginal bulbs (structures at where the uterovaginal canal meets the urogenital sinus) establish an opening. This results in an imperforate hymen – essentially a hymen that is closed off and doesn’t have a regular opening.
Newborn females often have extra hymenal tissue, which subsides as they grow older – usually by the age of one. Variations of the hymen shape are considered normal, with annular and fimbriated forms being the most common at birth. Other variations, however, including microperforated, septate, and cribriform hymens, are considered abnormal.
The microperforate hymen results when the cells in the center of the hymen do not degenerate as normal. Since the hymen is not a Müllerian structure, urinary tract problems are not commonly associated with an imperforate hymen. However, there have been some documented instances, which are believed to be the result of random development events.
Risk Factors and Frequency for Imperforate Hymen
Imperforate hymen, a rare condition in females at birth, occurs at a rate of 1 in 1000. Reports of urinary tract anomalies, however, are more prevalent, ranging from 4.2 per 10,000 births to 4.0 per 1000 births in countries across Europe and Asia. Although anomalies of the kidneys are often seen in patients with Müllerian abnormalities, it’s rare to find these issues in those with an imperforate hymen.
Due to this overall rarity, descriptions of multiple anomalies associated with an imperforate hymen are generally found in individual case reports. Approximately 20% of those presenting this condition experience urinary retention, while acute kidney injury is seen in about 2% of cases.
The frequency of other hymenal abnormalities is uncertain, with roughly 20 cases of microperforate hymen documented in existing medical literature.
Signs and Symptoms of Imperforate Hymen
An imperforate hymen is a condition where the hymen completely blocks the vagina. The symptoms can vary greatly, and can differ depending on the patient’s age at diagnosis, how blocked the vagina is, and the clinical progression. Spotting this condition in newborns can be challenging due to the extra hymen tissue often present.
Hydronephrosis (swelling of a kidney due to a build-up of urine) and pelvic masses can sometimes be detected in a 20-week prenatal ultrasound. Parents might notice symptoms like fever and fussiness in their infants, or they might not notice anything unusual, particularly when it comes to urination. Build-up of secretions in the vagina and cervix leading to a condition called mucocolpos may happen in infants on account of hormones they receive from their mother. The condition may show up early in children, with symptoms ranging from urinary retention, hydronephrosis combined with a urinary tract infection, to a kidney condition called acute lobar nephronia, resulting from blocked urine flow.
It’s not always easy to spot an imperforate hymen in infants during a physical exam. Even if an ultrasound shows bilateral hydronephrosis (swelling in both kidneys) and an extremely full bladder, a clear bulge might not be visible. This disorder can often be missed during the newborn exam due to the extra hymen tissue that’s typically present.
- May not be easy to spot during a physical exam
- May show bilateral hydronephrosis and full bladder on ultrasound
- Disorder can often be missed during newborn exam due to extra hymen tissue
In adolescents, an in-depth discussion about menstrual and sexual history might reveal crucial facts. For instance, a young woman might report having regular periods with a tiny hole in the hymen, known as a microperforate hymen. Pain related to the menstrual cycle that occurs due to the build-up of menstrual blood in the vagina and womb is also commonly reported. The build-up can cause a variety of pelvic symptoms, including pelvic and back pain, constipation, radiating pain due to irritation of the sacral plexus (a network of nerve fibres that supply the lower part of the body), and inability to pass urine. In some extreme cases, up to 3 liters of stale blood have been found in the vagina. Another unusual presentation is urethral coitus, where intercourse accidentally happens through the urethra. Symptoms linked to this include coital incontinence (leakage of urine during sex) and repeated urinary tract infections.
The initial steps of the genital exam in females are focused on checking the external structures to avoid missing any irregularities. In adolescents, the physical exam may reveal a blue, bulging mass near the perineum (area between the anus and vagina) that gets bigger with a technique called the Credé maneuver. This technique involves applying manual pressure on the lower abdomen, which can cause the blocked hymen to bulge outwards. If a blood-filled fallopian tube (hematosalpinx) breaks, the belly exam might indicate peritonitis (inflammation of the peritoneum, the lining of the abdomen). A rectal exam might reveal a tender swelling behind the vagina and might further show if any structures close to the vagina are missing.
Testing for Imperforate Hymen
A regular ultrasound at 20 weeks of pregnancy is a cost-effective way to check for any issues in the baby’s urinary tract, such as kidney irregularities, double kidney, or an enlarged kidney due to various causes, including normal enlargement or blockage, urinary retention, and backflow of urine from the bladder to the kidneys. An ultrasound is also vital after birth in case of an imperforate hymen – a condition where the hymen (a thin membrane partially covering the external vaginal opening) obstructs the vagina – to check for accumulated menstrual blood in the vagina and any associated urinary tract blockage, such as a distended bladder and/or enlarged kidneys.
If the ultrasound picks up anything concerning, doctors might use magnetic resonance imaging (MRI) for more detailed assessment. MRI is considered the best tool for evaluating anatomical abnormalities. In cases where a large mass in the pelvis makes it harder to see the pelvic anatomy, it’s recommended to get an MRI after surgery if there’s any worry about other irregularities in the urinary and genital systems.
Treatment Options for Imperforate Hymen
An imperforate hymen is a condition where a girl is born with a hymen (a thin membrane that covers the opening to the vagina) that’s missing a normal opening and blocks the flow of menstrual blood. Although in some cases this condition is identified when a baby is born, many girls may not discover they have an imperforate hymen until adolescence when they start their periods and experience severe abdominal pain due to trapped menstrual blood.
When symptoms become acutely severe, timely surgery is required to not only ease the discomfort but also prevent abdominal complications such as the backward flow of menstrual blood, endometriosis (a painful disorder where the tissue that normally lines the inside of the uterus grows outside), and fertility problems. Doctors emphasize that the surgery should be carried out under anesthesia in an operating room and not in an office setting to avoid the risk of infection and re-closure of the hymen.
Identification of an imperforate hymen before any severe symptoms can assist with planned surgery. Ideally, surgery should wait until puberty when the vaginal tissue is mature enough to heal well post-surgery. There are several treatment options available for imperforate hymen, which include different surgical methods and techniques, and even the use of specific lasers.
One traditional surgical method is called hymenectomy, it involves making a cross-shaped cut and removing four corners of the hymen, then the remaining edges are stitched together using dissolvable sutures. Other, more recent techniques aim to preserve as much of the hymen as possible, such as using a ring-shaped cut, or placing a special catheter (thin tube) and using estrogen cream to encourage tissue growth around it.
One study reported good results using laser treatment to create a new opening in the hymen for a group of 13 patients aged 12-16. They reported no scarring or narrowing of the hymen at their check-ups two weeks after the treatment and no reports of painful intercourse at 18 months post-treatment.
In the case of a microperforate hymen (a very small hole in the hymen), another less invasive treatment can be used. This involves progressive dilation of the vaginal opening under general anesthesia. Patients who had this treatment reported satisfactory results and did not face any problems using tampons later.
All these surgical methods should be decided after considering factors such as the patient’s age, overall health, the severity of their condition, and their personal preferences. Therefore, precise medical advice from a healthcare provider is crucial.
What else can Imperforate Hymen be?
If a newborn baby girl has a lump in the perineal region (the area between the anus and the vulva), medical professionals could consider that it might be one of following:
- A cyst near the urine passage (periurethral cyst)
- A misplaced and prolapsed urine sac (ectopic ureterocele)
- A type of cancer of the vagina (vaginal botryoid sarcoma)
A close look can help identify the nature of the lump. For instance, if the opening of the urine passage can be seen, it’s likely not a cyst. Ectopic ureteroceles that have moved out from the urine passage usually look congested. Vaginal botryoid sarcoma generally has multiple lobes or parts.
We must also consider and exclude from our diagnosis other vaginal anomalies that are due to abnormal development of the urinary and reproductive tract. These could coexist with the imperforate hymen, a condition where the hymen covers the whole vaginal opening. Some of these abnormalities are:
- A wall running across the vagina (transverse vaginal septum)
- Partial or complete absence of the vagina (vaginal atresia)
- Complete absence of the upper part of the vagina (vaginal agenesis)
Failing to detect these conditions can lead to further complications as their treatment differs. A rectal exam can provide more information about the genital tract and an MRI scan is the best method to examine the pelvis and exclude other anomalies.
We also need to remember that imperforate hymen can be a part of a syndrome like the McKusick-Kaufman syndrome, which includes extra fingers or toes, congenital heart disease, and accumulation of fluid in the vagina.
Hymenal polyps, harmless growths that can appear in newborns and normally disappear by themselves in a few weeks, must also be included in the list of possible conditions.
What to expect with Imperforate Hymen
Treating an imperforate hymen (a condition where a membrane blocks the vaginal opening) often completely resolves any symptoms the patient was experiencing. At times, this condition has been linked to newborn deaths due to breathing difficulties caused by a swollen abdomen. However, these instances are very rare.
Even with an infection after hymenectomy (a surgery to remove the membrane), the opening of the hymen generally remains unchanged. There is a theoretical risk of painful intercourse (dyspareunia), but this is not clearly defined in the available medical literature. Moreover, young girls who were treated with the placement of a Foley catheter (a tube used to drain urine from the bladder) to keep the hymenal structure intact, did not report severe pain during their first sexual experience.
After approximately 8.5 years of follow-up, women who had a hymenectomy sometimes reported painful periods (dysmenorrhea) without complaints of sexual dysfunction. Those who tried to conceive managed to have a successful live birth.
In another study, nearly 86% of women did not experience any pain during sex and were able to conceive after hymenectomy. Painful periods are likely due to endometriosis (a condition where tissue similar to the lining of the uterus grows outside of the uterus), which can be caused by backward flow of menstrual blood in women with an imperforate hymen.
A study with a long-term follow-up of 40 patients with either imperforate hymen or a blockage of the vagina by a transverse vaginal septa, found that patients with an imperforate hymen had significantly better success rates in full-term pregnancies.
Vaginal adenocarcinoma (a type of cancer starting from glandular cells) is rare but has occurred in a patient with a history of an imperforate hymen and vaginal adenosis. This patient was found to have vaginal adenosis (a condition when the cells lining of the vagina are replaced by glandular cells) after biopsy (tissue sample) two years after hymenectomy. The doctors believe that vaginal adenosis linked with an imperforate hymen can be due to abnormal tissue development during the early stages of the female reproductive system.
Another 20-year-old woman had granulated vaginal walls (thickened and rough tissue of the vagina) after the procedure, and her biopsy showed adenosis. In another case, a 14-year-old girl came for vaginal discharge and was found to have inflamed and granulated vaginal wall tissue. Her biopsy also showed adenosis.
Possible Complications When Diagnosed with Imperforate Hymen
A case has been recorded where a patient developed pelvic inflammatory disease, an infection of the female reproductive organs, after undergoing a minor surgical procedure called a hymenotomy. Even though the procedure was carried out under sterile conditions, the surgical site healed on its own within a day. The patient had to return for another surgical procedure called a hymenectomy two days later. A week after the surgery, however, the patient had a high fever, lower abdomen pain and an infection of the fallopian tube that had to be drained with the help of a CT scan. Based on this event, it’s advisable that incisions made in the hymen for diagnosis or symptom relief should not be taken lightly as they carry the risk of introducing bacteria into the body, which can lead to infection. Therefore, if a hymenectomy needs to be done urgently due to infection or urinary obstruction, it should be carried out in the operating room under sterile conditions.
Also, the risk of the hymen growing back after surgery has been noticed, especially in prepubertal patients because of the lack of estrogen in their bodies. For example, a two-day-old baby girl had a surgical cut and drainage of the hymen in the neonatal unit and was sent home the same day. Unfortunately, she had to return three weeks later with swelling around the vaginal area and her hymen bulging out. This time, her hymen was surgically removed in the operating room and stitches were placed in the margin of the hymenal ring to prevent it from growing back. It’s recommended to place a stitch or a dilator during surgery to reduce the risk of hymen regrowth.
Another case involved a 16-year-old girl who had to undergo hymen surgery four times due to her hymen re-growing. After her first three surgeries, she had a Foley catheter placed for 3 to 4 days. During her fourth surgery, she had her hymen removed with stitches, and a catheter was placed for two weeks. In a related method, Foley catheters were placed for two weeks with daily application of estrogen cream in a group of female patients aged approximately 14 years. Not carrying out hymenectomy properly with resulting closure and narrowing is believed to contribute to painful intercourse and possible infertility.
Post-surgery infection risk has not been studied on a large scale, but individual case outcomes have been reported. Some surgeons will give antibiotics before the surgery depending on the patient’s condition, such as potential infection in the fallopian tube. While not every surgeon uses antibiotics before surgery, it’s believed that hematocolpos, or a backup of menstrual blood in the vagina, provides an environment where bacteria can thrive.
Preventing Imperforate Hymen
An imperforate hymen, which is a condition where the opening to a girl’s vagina is blocked, can cause issues with the urinary tract. This happens because the buildup in the vagina creates a large mass in the pelvis area, which can block the urinary tract. This blockage can lead to problems like being unable to urinate, a swelling of the kidneys due to fluid buildup, or even sudden kidney damage.
Ultrasound, which is an affordable and non-invasive way to see inside the body, can help identify this blockage and the pelvic mass causing it. During the first few weeks of a baby girl’s life, those taking care of her should look out for bumps in the area around the genitals during cleaning. If you notice anything unusual, it’s a good idea to reach out to a pediatrician or a specialist.
If an imperforate hymen is discovered, it’s important to stick to the recommended checkups. A surgical procedure to make an opening in the hymen, known as hymenectomy, will need to be timed correctly, usually before the girl starts her menstrual cycles.
