Transvaginal ultrasound is a method of imaging the genital tract in women. The ultrasound machine sends out high-frequency sound waves, which bounce off body structures to create a picture.

With the transvaginal technique, the ultrasound transducer (a hand-held probe) is inserted directly into the vagina. It is therefore closer to pelvic structures than with the conventional transabdominal technique (with the probe on the skin of the abdomen), providing superior image quality. This test can be used during pregnancy. (See also pregnancy ultrasound.)

You will be lying down on a table. The transducer is a long probe, covered with a condom and a sterile lubricant, that is inserted into the vagina. The health care provider will then move the probe within the vaginal cavity to scan the pelvic structures.

The examination is done with your bladder empty. Sometimes, a transabdominal ultrasound is done just before a transvaginal ultrasound to look at organs in your abdomen.

If so, you may be asked to drink several glasses of water without voiding before the transabdominal exam. Then, you will be asked to empty your bladder after the transabdominal test and before the transvaginal exam.

There may be mild discomfort from the pressure of the vaginal probe.

Transvaginal ultrasound is used to evaluate a variety of abnormalities of the female genital tract. Some of these include the endometrium of women with infertility problems or abnormal bleeding; sources of unexplained pain; congenital malformations of the uterus and ovaries; ovarian tumors and cysts; possible pelvic infection; and causes of infertility.

Transvaginal ultrasound is also used during pregnancy to identify normal intra-uterine pregnancy; ectopic pregnancy; fetal heartbeat; and many abnormalities of the uterus, placenta, and associated pelvic structures that are incompletely seen with conventional transabdominal ultrasound.

The pelvic structures and/or fetus are normal.

Abnormal endovaginal ultrasound results may be due to many conditions.

Some of the abnormalities that may be found in non-pregnant women include:

• Cancers of the uterus, ovaries, vagina, and other pelvic structures
• Non-cancerous growths of the uterus and ovaries
• Ovarian torsion
• Areas of infection including pelvic inflammatory disease
• Congenital malformations

Some of the abnormalities that may be found in pregnant women include:

• Ectopic pregnancy and potential miscarriage
• Multiple pregnancies
• Fetal death
• Placental abnormalities including placenta previa and placental abruption
• Tumors of pregnancy including gestational trophoblastic disease

There is no documented biologic effect on patients and their fetuses with the use of current ultrasound techniques. No ionizing radiation is involved.

Occasionally saline is injected into the uterus of non-pregnant patients to evaluate the uterine cavity. This is called sonohysterography. The vaginal probe can also assist in obtaining biopsies of abnormal areas or in draining fluid.