A transvaginal (or endovaginal) ultrasound is a radiological examination of the female pelvic structures using a transducer (probe) that is inserted into the vagina. Since the transvaginal probe is closer to the pelvic structures than a standard probe on the surface of the abdomen, this examination is used when more information is needed after a transabdominal ultrasound has been performed. In constrast to a transabdominal pelvic ultrasound, the bladder should be empty during this test to decrease artifacts and allow for better visualization of the pelvic region.

The examination involves placing the patient in a lithotomy position on an examination table, similar to the positioning during a gynecological exam. An elongated transducer is covered with a condom and sterile lubrication and is inserted into the vagina. Images appear on a monitor and the examiner will scan all the visible pelvic structures and record some images for further review.

The indications for a transvaginal ultrasound include the work-up of pelvic pain (which may be related to conditions including fibroids, ovarian cysts or carcinoma, endometriosis, and ectopic pregnancy; furthermore, this study is often performed in pregnant women to evaluate the status of the amniotic sac, placenta, and fetus.