The hymen is a thin membrane. It most often covers part of the opening of the vagina. Imperforate hymen is when the hymen covers the whole opening of the vagina.

Imperforate hymen is the most common type of blockage of the vagina.

Imperforate hymen is something a girl is born with. No one knows why this happens. There is nothing that the mother did to cause it.

Girls can be diagnosed with imperforate hymen at any age. It is most often diagnosed at birth or later at puberty.

At birth or early childhood, the health care provider may see that there is no opening in the hymen during a physical exam.

At puberty, girls usually do not have any problems from an imperforate hymen until they start their period. The imperforate hymen blocks the blood from flowing out. As the blood backs up the vagina, it causes:

• Mass or fullness in the lower part of the belly (from the buildup of blood that can't come out)
• Stomach pain
• Back pain
• Problems with urinating and bowel movements

The provider will do a pelvic exam. The provider may also do a pelvic ultrasound and imaging studies of the kidneys. This is done to ensure that the problem is imperforate hymen rather than another problem. The provider may recommend that the girl see a specialist to make sure that the diagnosis is imperforate hymen.

A minor surgery can fix an imperforate hymen. The surgeon makes a small cut or incision and removes the extra hymen membrane.

• Girls who are diagnosed with imperforate hymen as babies most often have surgery when they are older and have just started puberty. The surgery is done in early puberty when breast development and pubic hair growth have begun.
• Girls who are diagnosed when they are older have the same surgery. The surgery allows retained menstrual blood to leave the body.

Girls recover from this surgery in a few days.

After surgery, the girl may have to insert dilators into the vagina for 15 minutes each day. A dilator looks like a tampon. This keeps the incision from closing on itself and keeps the vagina open.

After girls recover from the surgery, they will have normal periods. They can use tampons, have normal sexual intercourse, and have children.

Contact the provider if:

• There are signs of infection after surgery, such as pain, pus, or fever.
• The hole in the vagina seems to be closing (the dilator will not go in or there is a lot of pain when it is inserted).

Kaefer M. Management of abnormalities of the genitalia in girls. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 47.