What Does an Abnormal Transvaginal Ultrasound Mean?

Few things are as scary as getting a phone call or letter telling you your transvaginal ultrasound was “abnormal.” Before you jump to conclusions, it can be helpful to understand what “abnormal” means from a medical standpoint. An abnormal result does not necessarily mean there is something terribly wrong. Instead, it means that the technician or radiologist identified something that was outside of normal parameters and needs further evaluation. 

Here, we explain what a transvaginal ultrasound is, what types of findings are typically labeled as abnormal, what those findings often indicate, and what to expect next. Consider this your user-friendly supplement to what your doctor tells you.

What Is a Transvaginal Ultrasound?

A transvaginal ultrasound (sometimes abbreviated TVS or TVUS) involves having an ultrasound scanner placed inside you. A probe the width of a large tampon at its widest point is covered with a sheath and lubricating gel then inserted gently into your vagina. It emits sound waves which bounce off your pelvic organs and produce a picture on a screen.

The probe's proximity to the organs being studied creates clearer, more detailed images than an abdominal ultrasound. For this reason, many doctors prefer a transvaginal scan to explore gynaecological issues.

Doctors can use this scan to identify unusual growths and determine causes of pelvic pain or abnormal bleeding. It may also help confirm pregnancies or monitor early fetal growth.

A sonographer or radiologist performs the test. Both are medical professionals trained to conduct ultrasounds. Unlike some tests, you don’t need to fill your bladder first. Having your period will not interfere with the scan.

The exam shouldn’t hurt, but you may feel pressure. It should last about 15 to 30 minutes.

Read More: Is a Transvaginal Ultrasound Painful or Just Uncomfortable?

Why Might You Be Referred for One?

Transvaginal ultrasound is the first-line imaging test for the assessment of abnormal uterine bleeding in both premenopausal and postmenopausal women.

Common reasons a gynaecologist or GP might order one include:

• Unexplained pelvic pain

• Heavy, irregular, or unexpected vaginal bleeding

• Post-menopausal bleeding

• Suspected fibroids, cysts, or polyps

• Monitoring fertility or ovulation

• Investigating possible ectopic pregnancy

• Checking an IUD for correct placement

• Following up after an unusual finding on a pelvic examination

  
  

What Does "Abnormal" Actually Mean?

Here is one thing to remember: An abnormal transvaginal ultrasound DOES NOT mean something bad. It means that something was seen that was NOT considered normal. It means that something was seen that may or may not be within normal limits and that it needs further evaluation.

During Private Ultrasound Scanning Services, specialists carefully assess such findings and recommend appropriate follow up if needed. There are numerous conditions that can cause an abnormal result, and most are harmless or treatable with timely care and proper diagnosis.

Common Abnormal Findings on a Transvaginal Ultrasound

Uterine Fibroids

Fibroids are non-cancerous tumours that grow in or on the uterus. Depending on their size and location, they can cause heavy menstrual bleeding, pelvic pain, or no symptoms at all.

Fibroids arise from the uterine muscle and can occupy various positions within the uterus or surrounding structures. The degree to which a fibroid projects into the endometrial cavity is clinically important as it helps determine whether it can be removed by hysteroscopy. They are extremely common and often discovered incidentally during a routine scan.

Endometrial Thickening

The endometrium is the lining of the uterus, and its thickness changes throughout the menstrual cycle. When it appears thicker than expected, this may indicate hormonal imbalance, polyps, endometrial hyperplasia, or, less commonly, endometrial cancer.

In women with post-menopausal bleeding, measurement of endometrial thickness by transvaginal ultrasound should be the first-line test. Women can be reassured and discharged if the endometrial thickness measures less than 4mm, as the risk of endometrial cancer at this level is very low. Further endometrial assessment is indicated if the measurement exceeds 4mm.

Even if the endometrial thickness falls below the threshold, focal thickening and heterogeneity of the endometrium should be considered abnormal and further investigation planned.

For premenopausal women, the picture is slightly more nuanced because the endometrium naturally thickens and thins across the cycle. Clinically used criteria suggest that endometrial pathology in premenopausal women may be suspected at a thickness above 8mm in the proliferative phase and above 16mm in the secretory phase.

Ovarian Cysts

Ovarian cysts are fluid-filled sacs that form on or within the ovaries. Many are completely harmless and resolve on their own without treatment. Simple fluid-filled cysts are often harmless and resolve on their own. More complex or solid cysts may require monitoring or further investigation to rule out conditions such as endometriomas (a sign of endometriosis) or, in rarer cases, ovarian tumours.

Uterine Polyps

Polyps are small, fleshy growths attached to the inner wall of the uterus. They can cause irregular bleeding between periods, heavy periods, or bleeding after the menopause. Transvaginal ultrasound can identify structural causes of abnormal uterine bleeding including polyps, adenomyosis, fibroids, hyperplasia, and malignancy.

Adenomyosis

Adenomyosis occurs when tissue similar to the uterine lining grows into the muscular wall of the uterus. The diagnosis of adenomyosis by ultrasound is best performed via the transvaginal approach and its clinical significance is most notable in symptomatic women. It commonly causes heavy, painful periods and an enlarged uterus.

Pelvic Inflammatory Disease (PID)

Pelvic inflammatory disease, an infection of the reproductive organs, may show as fluid collections or swelling in the uterus or fallopian tubes on a transvaginal scan. Left untreated, it can affect fertility, so early detection matters.

Ectopic Pregnancy

A transvaginal ultrasound can help determine if a pregnancy is growing outside the uterus, which can be a life-threatening condition. If you have a positive pregnancy test alongside pelvic pain or unusual bleeding, a transvaginal scan is usually arranged promptly for this reason.

Congenital Uterine Abnormalities

Some women are born with variations in uterine shape, such as a bicornuate (heart-shaped) uterus or a septate uterus. These may be discovered incidentally during a scan and can sometimes be linked to recurrent miscarriage or difficulty conceiving. Three-dimensional transvaginal ultrasound allows for classification of congenital uterine malformations using coronal reconstruction.

What Happens After an Abnormal Result?

The next steps depend entirely on what was found, your symptoms, and your medical history. Here is a general idea of what to expect:

1. Discussion with your clinician. Results are most often reported the same day and sent back to your doctor, who will discuss the findings with you. If your referring doctor is a GP, you should book an appointment within two weeks of the scan to discuss the results.

2. Repeat or follow-up imaging. For findings that need monitoring over time, such as a small cyst, a follow-up scan may be all that is needed.

3. Additional blood tests. These might include hormone panels, CA-125 (an ovarian cancer marker), or other relevant tests depending on the suspected diagnosis.

4. Endometrial biopsy. If abnormal changes are found in the womb, a biopsy may be needed to find the cause. A biopsy involves taking samples of the womb lining, which are sent to a laboratory to be examined under a microscope.

5. Hysteroscopy or laparoscopy. A hysteroscopy uses a thin camera inserted through the cervix to examine the inside of the uterus. A laparoscopy is a keyhole surgical procedure to look at the pelvic organs from the outside. Both allow for direct visualisation and, if needed, tissue sampling.

6. Saline Infusion Sonography (SIS). In some cases, a gynaecologist may recommend saline infusion sonography, a technique that involves introducing a small amount of saline into the uterus to better outline the uterine cavity and improve visualisation of the endometrium and related structures.

   
   

When to Seek Prompt Assessment

Most abnormal findings are not emergencies, but some situations call for a timely appointment rather than waiting. Contact a gynaecology clinic promptly if you experience:

• Post-menopausal bleeding of any amount

• Sudden or severe pelvic pain

• Suspected ectopic pregnancy (positive pregnancy test plus one-sided pain or unusual bleeding)

• Bleeding between periods that has started recently and has no obvious explanation

At myGynaePlus, the team offers expert ultrasound scanning services as part of a wider range of gynaecology services. Scans are performed by senior specialists using high-resolution imaging equipment, and results are discussed with you clearly and without unnecessary medical jargon.

Does an Abnormal Scan Mean Cancer?

The question I’m asked most frequently by women is “Does it mean cancer?” Unfortunately for catchy blog headlines, the truth is: not usually. Most abnormal findings on a transvaginal ultrasound are benign. Fibroids, polyps and simple ovarian cysts make up a large percentage of abnormal findings. These particular conditions pose no risk of cancer.

On the rare occasions where cancer is a concern (such as with endometrial thickening or a complex mass on the ovary), the ultrasound can’t diagnose cancer on its own. You need a biopsy of the tissue to do that. Think of your vaginal ultrasound as a screening and triage tool. It lets your clinician know if they should investigate further. It does not tell you if you have cancer.

If your endometrial lining measures 4mm or less, there is a greater than 99% chance you do not have endometrial cancer. This is assuming you are a postmenopausal woman who presented with bleeding, but this is an excellent statistic for the many women who receive an ultrasound result just a few millimeters thicker than that.

A Note on the Psychological Side

Having a scan that comes back abnormal can feel very anxiety-inducing even if the finding is something minor. That is completely normal. Usually what reassures people is being given information as soon as possible, knowing what the next step is and that something is being done.

If you’re waiting on results or next steps and are feeling anxious about it, try calling the clinic to ask how long it will be until you get your answer. A good gynaecology service will go over your results with you and ensure you leave that consultation knowing what it means for you.

myGynaePlus clinic was built with that principle in mind. Appointments are about having conversations, not ticking boxes. The team will take the time to explain things to you in terms you’ll understand.

FAQs

1. Can a transvaginal ultrasound miss something serious? 

No imaging test is perfect. A transvaginal ultrasound provides detailed pictures, but it cannot confirm a diagnosis on its own. If something looks concerning, your doctor will arrange further tests, such as a biopsy or MRI, to get a clearer answer. Following your clinician's guidance on next steps is the best course of action.

2. How long does it take to get results from a transvaginal ultrasound? 

In most UK clinics, the images are reviewed and a report prepared on the same day or within a day or two. Your referring doctor then receives the report and should discuss it with you within about two weeks, though urgent findings are usually flagged sooner.

3. What does a thickened endometrium on a transvaginal ultrasound mean? 

It means the lining of your uterus appears thicker than expected. This can be caused by hormonal changes, polyps, fibroids, or endometrial hyperplasia. In post-menopausal women with bleeding, further investigation is recommended if the thickness exceeds 4mm. In many cases, the cause turns out to be benign and manageable.

4. Can a transvaginal ultrasound detect ovarian cancer? 

It can detect abnormal masses or cysts on the ovaries, which may prompt further investigation. However, it cannot diagnose ovarian cancer on its own. A blood test measuring the CA-125 marker and, in some cases, an MRI or biopsy are used alongside the scan to reach a diagnosis.

5. Is a transvaginal ultrasound safe during pregnancy? 

Yes. The procedure does not use radiation and is considered safe at any stage of pregnancy. In fact, transvaginal ultrasound is the preferred method in early pregnancy precisely because it produces clearer images than an abdominal scan at that stage, helping confirm the pregnancy is developing in the right place and at the right rate.