A transvaginal, or endovaginal, ultrasound is a safe, straightforward way for doctors to examine the internal organs of the female pelvic region. It typically does not cause pain.

An ultrasound uses high-frequency sound waves to produce detailed images of internal organs.

Unlike X-rays, ultrasound scanning does not involve radiation, which means that it has no known side effects and is very safe.

In this article, we explain the uses of transvaginal ultrasounds and how to prepare for one. We also describe what to expect during the scan.

Share on Pinterest
Illustration by Diego Sabogal

A healthcare professional uses an ultrasound to create images of the inside of the body. High-frequency sound waves bounce off the internal organs and form these images.

There are two ways to perform an ultrasound — abdominally and transvaginally.

A transvaginal ultrasound is an internal scan of the female reproductive organs. It involves inserting a small ultrasound probe, called a transducer, into the vagina to produce incredibly detailed images of the organs in the pelvic region.

It may be necessary to use a transvaginal ultrasound to examine the:

  • vagina
  • cervix
  • uterus
  • fallopian tubes
  • ovaries
  • bladder

Transvaginal ultrasounds can check for:

  • the shape, position, and size of the ovaries and uterus
  • the thickness and length of the cervix
  • blood flow through the organs in the pelvis
  • the shape of the bladder and any changes
  • the thickness and presence of fluids near the bladder or in the:
    • fallopian tubes
    • myometrium, the muscle tissue of the uterus
    • endometrium

Doctors may request a transvaginal ultrasound for a variety of reasons. For example, it might be necessary to identify the cause of:

  • pelvic pain
  • unexplained vaginal bleeding
  • infertility
  • abnormal results of a pelvic or abdominal exam

These scans can also help diagnose:

In addition, it can check for the presence of an intrauterine contraceptive device.

Doctors may request a transvaginal ultrasound during pregnancy, as it can help:

  • check the heartbeat of the fetus
  • confirm the date of delivery
  • assess the condition of the placenta
  • check for an ectopic pregnancy
  • monitor pregnancies with a higher risk of pregnancy loss

A transvaginal ultrasound is not typically painful, but the insertion of the probe may be uncomfortable.

The healthcare professional performing the scan first covers the probe in a sheath and lubricating gel before inserting it slowly into the vagina to a depth of around 5–8 centimeters (cm). There may be mild pressure or discomfort at this stage.

There are no after-effects of a transvaginal ultrasound, and a person can return to their regular activities afterward.

A pelvic ultrasound is a noninvasive exam that produces images of the internal reproductive organs to help healthcare professionals diagnose certain conditions.

Doctors may use the term “pelvic ultrasound” to describe both a transvaginal and a transabdominal ultrasound. During a transabdominal ultrasound, the person performing the scan uses the probe outside the abdomen.

Another name for a transabdominal ultrasound is an external pelvic ultrasound. A person lies on their back on an examination table, and the healthcare professional applies a warm gel to the lower section of the person’s abdomen. Then, they move a probe over the area.

The person might feel slight pressure on their abdomen, but the scan is not painful. The probe uses sound waves to form an image of the internal organs and structures of the pelvic area.

By comparison, a transvaginal ultrasound can provide more close-up images of the internal organs than an external pelvic ultrasound.

A transvaginal ultrasound is a simple, painless scan that requires very little preparation. A person should be able to eat and drink normally before the appointment.

At the appointment, a healthcare professional will describe any necessary steps. A person needs to empty their bladder right before the scan, and anyone using a tampon should remove it.

A doctor or a specially trained technician, called a sonographer, performs most transvaginal ultrasounds.

A person needs to undress from the waist down and put on a hospital gown. Next, they lie on an examination table with their knees bent. The healthcare professional uses a sheet to cover the person’s lower body.

The transducer resembles a wand and is slightly larger than a tampon. The sonographer or doctor covers the transducer with a sheath and lubricating gel before inserting it 5–8 cm into the vagina.

Once the transducer is in place, it produces sound waves that bounce off of the internal organs and relay information. To create a complete picture and bring different areas into focus, the sonographer or doctor rotates the transducer. This tool transmits the information directly to a screen.

The images display immediately on the screen, making it possible for the person and the healthcare professional to monitor the scan in real-time.

The whole process may last 15–30 minutes.

Unlike a traditional X-ray, a transvaginal ultrasound does not use radiation. As a result, it is very safe — there are no known risks.

It is also safe to perform transvaginal ultrasounds during pregnancy — there is no risk to the fetus.

During the insertion of the transducer, there may be some pressure and minimal discomfort. This feeling should go away after the scan.

It is essential to let the sonographer or doctor right away if anything feels particularly uncomfortable.

As the Miscarriage Association confirms, there is no evidence that a transvaginal ultrasound can harm a fetus or cause pregnancy loss.

If a person notices bleeding after a transvaginal ultrasound, this may be because blood has collected higher up in the vagina, and the transducer may have dislodged it.

People may have a transvaginal ultrasound in the first 11–12 weeks of pregnancy. After 11–12 weeks, it may be more common to have a transabdominal ultrasound. However, in some cases, doctors may still request a transvaginal ultrasound, which is a more accurate and detailed scan.

Transvaginal ultrasounds are safe up until a person’s water breaks.

If a specialist is present at the ultrasound, the person may hear the results immediately. If a sonographer does the scan, they send the images to a radiologist for analysis. The radiologist then sends a written report of the results to the person’s doctor.

Either way, it is important to discuss the results with a doctor, who can provide more information. This discussion can take place in person or over the phone.

A transvaginal ultrasound is a safe scan, with no known risks. People might experience some light discomfort during it, but this should go away afterward.

The ultrasound may take 15–30 minutes, and the results may be available immediately or within a few days, depending on whether a doctor was present during the scan.

If a person experiences extreme discomfort during the ultrasound, the doctor or sonographer may perform a transabdominal ultrasound instead. This type does not involve inserting the scanning tool into the vagina.