Hymen Abnormalities

The hymen is a thin ring-like shaped membrane bordering the vaginal opening. Hymens can differentiate in the shapes that they take, however, the crescent half-moon shape is the most common. This shape is suitable for allowing menstrual blood to easily emanate from a woman’s vagina.

However many women can be born with congenital irregularities that affect the hymen. These structural abnormalities of the hymen can affect the function of a woman’s body as she develops. An affected hymen can cause issues with menstruation, vaginal intercourse, and pregnancy.

When the shape of the hymen disrupts the normal functionalities of the body they are classed as Hymeneal disorders or abnormalities, these variations in the development of the hymen in the embryo are common. They include an imperforate hymen, micro-perforate hymen, septate hymen, and cribriform hymen.

An imperforate hymen is one in which the thin membrane of connective tissue completely covers the vaginal opening, causing an absence of an external vaginal opening, and there to be no hole for menstrual blood to flow from the vagina. It is a rare anomaly of the vagina, but not uncommon in the population. Of the four hymeneal abnormalities an imperforate hymen is the most common, and the most extreme type of occlusion.

A micro-perforate hymen is one where the normal vaginal opening is almost entirely covered, with only a small hole for menstrual blood and/or vaginal mucus to emanate from the vagina. The menstrual blood is able to flow through the minute hole in the hymen, but the rate at which it emanates is slow, and therefore a woman’s period may last longer than the usual four to seven days.

A septate hymen is when an irregularity occurs in the formation of the thin hymeneal membrane where a small strip of tissue connects vertically in the middle, creating two small external vaginal openings.

A cribriform hymen is one of the rarer forms of hymeneal abnormalities where the thin membrane that covers the vaginal opening, instead of having one large opening, has multiple small openings.

Most women with hymen abnormalities will not be aware of this until it presents an issue or is found in a routine exam, however some women experience symptoms depending on the extent or type of the irregularity.

Symptoms of an imperforate hymen:

  • Most women with an imperforate hymen experience a menstrual cycle, but have an absence of menstrual bleeding, because they have no external vaginal opening.
  • Even after puberty has begun, no blood will emanate from the vagina as the thin hymeneal membrane will cover it.
  • The buildup of the blood in the vagina will lead to an abdominal mass or bulge in the lower abdomen, this can cause abdominal and back pain, difficult or painful urination and bowel movements may also be felt around the first period.
  • In a newborn baby, there can be a bulge in the hymeneal membrane due to the buildup of mucus in the vagina.

Symptoms of a microperforate hymen:

  • Due to the minute opening in the hymeneal membrane, blood may be allowed to emanate from the vagina but the menstrual periods and bleeding will last longer than the usual four to seven days.
  • Women will experience difficulty or pain inserting a tampon and trouble removing it once it becomes full with blood.
  • Tearing of the hymen during sexual intercourse can cause pain or bleeding.

Symptoms of a septate or cribriform hymen:

  • Women will experience trouble with inserting a tampon into the vagina and difficulty removing it once it becomes full with blood.
  • They can also experience difficulty and pain during sexual intercourse.

Hymeneal abnormalities are most commonly congenital and will form during fetal development, and the cause is primarily unknown. But some studies suggest that irregularities such as an imperforated hymen could also be caused by scarring from sexual abuse or perforation.

An imperforate hymen is one of the most common obstructive irregularity of the female genital system, with the prevalence in the population varying from 0.1-0.01%, and resulting from abnormal or irregular fetal development. A microperforate or cribriform hymen is caused by improper or irregular hymeneal formation during fetal development. A septate hymen develops due to the vaginal tubes not fusing together correctly during fetal development.

An imperforate hymen restricts the drainage of menstrual and other fluids from the vagina which can cause hydrocolpos, an abnormal swelling of the vagina, or hydrometrocolpos, abnormal swelling of both the vagina and uterus. Due to the occlusion of the vagina by the thin hymeneal membrane it causes an inability to use tampons or participate in vaginal intercourse.

Due to the minute hole in a microperforate hymen, the insertion of a tampon may be difficult or impossible. Tampon use and vaginal intercourse may also be excessively painful and may result in tearing or bleeding.

Complications caused by a septate hymen are most commonly due to the inability to use a tampon, or the difficulty removing one after use. If the septate hymen is ripped or torn to free the tampon or during sexual intercourse it may cause damage to the vaginal opening, and discomfort or pain.

A cribriform hymen allows menstrual and other fluids to emanate from the vagina, but restricts tampon use, examination of the pelvis, and vaginal intercourse.

Many women do not recognise that they have an irregular hymen until they experience symptoms or it is discovered in a regular exam. Most commonly the abnormality, if an imperforate hymen, is found in newborns due to abnormal swelling caused by mucus building in the vagina. However if the hymen irregularities are not as severe or the mucus does not build up, it may not be discovered until puberty.

It can be discovered due to the lack of menstrual bleeding during her first period in the case of an imperforate hymen, or difficulties in the use of a tampon for the other abnormalities. The inability for the menstrual fluid to drain can cause swelling of the abdomen and severe pain.

The treatments are dependent on the extent of the irregularity of the hymen, and the cause of the blockage to the vagina.

For an imperforate hymen, surgery is required as there is no hole to correct. Only a small incision with no anesthetic is required to remove the excess hymeneal membrane, and the fluid is drained from the vagina to alleviate the pain and discomfort. Recovery will only take a few days, but if the incision looks to be closing, a dilator may have to be used until the wound is healed and stable. After the surgery, the menstrual cycle will proceed normally, the ability to have vaginal intercourse will be retained, and the ability to have children is not affected.

For a microperforate hymen surgery may not be required as the irregularity may resolve itself over time, and age may cause spontaneous enlargement of the external vaginal opening, or it may tear away with a tampon, or through vaginal intercourse. However if the issue is not resolved naturally, a minor surgery may be needed to correct the hymeneal tissue and create a normal sized vaginal opening, which allows normal menstrual flow.

For a septate hymen the extra hymeneal tissue may either be removed via surgery or can be torn away during tampon use or vaginal intercourse, however, surgery may help avoid the pain, discomfort, and bleeding that could occur.

For a cribriform hymen the treatment is similar as to the treatment for a microperforate hymen.