Transvaginal ultrasound is a type of pelvic ultrasound. It is used to look at a woman's reproductive organs, including the uterus, ovaries, cervix, and vagina. Transvaginal means across or through the vagina.

See also: Pregnancy ultrasound

You will lie down on a table with your knees bent and feet in holders called stirrups. The health care provider will place a probe, called a transducer, into the vagina. The probe is covered with a condom and a gel. The probe sends out sound waves, which reflect off body structures. A computer receives these waves and uses them to create a picture. The doctor can immediately see the picture on a nearby TV monitor.

The health care provider will move the probe within the area to see the pelvic organs. This test can be used during pregnancy.

In some cases, a special transvaginal ultrasound method called saline infusion sonography (SIS), also called sonohysterography or hysterosonography, may be needed to more clearly view the uterus.

This test requires saline (sterile salt water) to be placed into the uterus before the ultrasound. The saline helps outline any abnormal masses, so the doctor can get a better idea of their size.

SIS is not done on pregnant women.

You will be asked to undress, usually from the waist down. A transvaginal ultrasound is done with your bladder empty.

The test is usually painless, although some women may have mild discomfort from the pressure of the probe. Only a small part of the probe is placed into the vagina.

Transvaginal ultrasound can help diagnose the cause of certain types of infertility, pelvic pain, abnormal bleeding, and menstrual problems. It can show the lining of the uterus (endometrium). The test may reveal:

• Ovarian cysts
• Ovarian tumors
• Pelvic infection
• Uterine fibroids
• Uterine lining polyps
• Thickened uterine lining in cases of postmenopausal bleeding

Transvaginal ultrasound is also used during pregnancy to monitor the growth of the fetus, listen to the unborn baby's heart beat, and to check for ectopic pregnancy and other potential problems.

The pelvic structures or fetus are normal.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

An abnormal result may be due to many conditions. Some problems that may be seen include:

• Birth defects
• Cancers of the uterus, ovaries, vagina, and other pelvic structures
• Infection, including pelvic inflammatory disease
• Non-cancerous growths of the uterus and ovaries (such as cysts or fibroids)
• Twisting of the ovaries

Some problems or conditions that may be found specifically in pregnant women include:

• Ectopic pregnancy
• More than one fetus (twins, triplets, etc.)
• Miscarriage
• Placenta previa
• Placental abruption
• Shortened cervix, which increases the risk for preterm delivery or late miscarriage
• Tumors of pregnancy including gestational trophoblastic disease

There are no known harmful effects of transvaginal ultrasound on humans.

Unlike traditional x-rays, there is no radiation exposure with this test.

Katz VL. Diagnostic procedures: Imaging, edometrial sampling, endoscopy: Indication and contraindications, complications. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa : Mosby Elsevier; 2007: chap 11.

Goldstein RB. Saline Infusion Sonohysterography. Ultrasound Clin. April 2006; 1(2); 385-414.

Goldstein SR. Abnormal Uterine Bleeding: The Role of Ultrasound. Radiol Clin North Am. November 2006; 44(6); 901-910.