Uterine fibroids are among the most common non-cancerous growths affecting women of reproductive age. Many women with fibroids have no symptoms, while others experience heavy menstrual bleeding, pelvic pain, infertility, or pressure on nearby organs.
If your doctor suspects you have fibroids, one of the first imaging tests they may recommend is a pelvic ultrasound. But can ultrasound detect fibroids accurately?
The short answer is yes. Ultrasound is the first-line imaging test for evaluating suspected uterine fibroids and can identify most fibroids, assess their size, location, and number. However, like every medical test, ultrasound has some limitations.
This article explains how ultrasound detects fibroids, what the scan can show, when additional imaging may be needed, and how to prepare for the examination.
What Are Uterine Fibroids?
Uterine fibroids, also called leiomyomas or myomas, are benign (non-cancerous) tumors that develop from the smooth muscle of the uterus.
Fibroids can vary greatly in size—from tiny growths that are barely visible to large masses that enlarge the uterus. A woman may have one fibroid or several.
Although the exact cause is not fully understood, hormones such as estrogen and progesterone are believed to play an important role in their growth.
Can Ultrasound Detect Fibroids?
Yes. Ultrasound is highly effective at detecting most uterine fibroids and is usually the first imaging test recommended when fibroids are suspected.
During the examination, high-frequency sound waves create images of the uterus and surrounding pelvic organs. Fibroids often appear as well-defined solid masses within or attached to the uterus.
Ultrasound can help determine:
- Whether fibroids are present.
- The number of fibroids.
- Their size.
- Their location within the uterus.
- Whether they may be affecting nearby structures.
This information helps healthcare providers decide whether further evaluation or treatment is needed.
Types of Ultrasound Used to Detect Fibroids
Transabdominal Pelvic Ultrasound
A transabdominal ultrasound is performed by moving a transducer over the lower abdomen.
A comfortably full bladder is usually required because it helps improve visualization of the uterus and pelvic organs.
This method is commonly used as the initial examination.
Transvaginal Ultrasound
A transvaginal ultrasound uses a specially designed ultrasound probe inserted gently into the vagina.
Because the probe is closer to the uterus, it often provides more detailed images, especially for small fibroids or fibroids located within the uterine wall.
In many cases, both transabdominal and transvaginal ultrasound may be performed during the same visit to obtain the most complete assessment.
What Types of Fibroids Can Ultrasound Identify?
Ultrasound can identify fibroids in different locations, including:
Intramural Fibroids
These develop within the muscular wall of the uterus and are the most common type.
Subserosal Fibroids
These grow on the outer surface of the uterus and may press against nearby organs such as the bladder or bowel.
Submucosal Fibroids
These project into the uterine cavity and are more commonly associated with heavy menstrual bleeding and fertility problems.
Pedunculated Fibroids
These fibroids are attached to the uterus by a narrow stalk and may occur inside or outside the uterus.
Symptoms That May Suggest Fibroids
Your healthcare provider may recommend a pelvic ultrasound if you experience:
- Heavy menstrual bleeding.
- Prolonged menstrual periods.
- Pelvic pain or pressure.
- Lower abdominal swelling.
- Frequent urination.
- Difficulty emptying the bladder.
- Constipation due to pressure on the bowel.
- Pain during sexual intercourse.
- Difficulty becoming pregnant.
- Recurrent pregnancy loss in selected cases.
These symptoms can also occur with other medical conditions, so imaging and clinical evaluation are important.
What Can Ultrasound Tell Your Doctor?
A pelvic ultrasound provides valuable information, including:
- Uterine size.
- Fibroid size.
- Number of fibroids.
- Fibroid location.
- Changes in the uterine shape.
- Ovarian appearance.
- Other pelvic abnormalities that may explain your symptoms.
This information helps guide treatment planning and follow-up.
Can Ultrasound Miss Fibroids?
Although ultrasound is very effective, it is not perfect.
Some fibroids may be difficult to detect if they are:
- Very small.
- Hidden by bowel gas.
- Located in difficult-to-visualize areas.
- Present in women with a significantly enlarged uterus or certain body types.
If ultrasound findings are unclear or more detailed evaluation is needed, your healthcare provider may recommend additional imaging such as magnetic resonance imaging (MRI).
How Do You Prepare for a Fibroid Ultrasound?
Preparation depends on the type of ultrasound.
For a transabdominal pelvic ultrasound, you may be asked to:
- Drink approximately 500–1,000 mL of water 30–60 minutes before your appointment.
- Avoid urinating until after the examination.
- Wear comfortable clothing.
For a transvaginal ultrasound, you are usually asked to empty your bladder before the examination.
Always follow the instructions provided by your imaging center.
Is Ultrasound Safe?
Yes.
Diagnostic ultrasound uses sound waves rather than ionizing radiation and is widely regarded as a safe imaging technique when performed by trained healthcare professionals for appropriate medical reasons.
Frequently Asked Questions
Can ultrasound confirm that a fibroid is cancer?
No. Ultrasound can identify a uterine mass that appears consistent with a fibroid, but it cannot reliably determine whether a mass is benign or malignant. If there are unusual features or concerns, additional investigations may be recommended.
Can fibroids be seen during pregnancy?
Yes. Fibroids are often detected during pregnancy ultrasounds. Their significance depends on their size, number, and location, and management should be guided by an obstetric healthcare professional.
Can ultrasound detect very small fibroids?
Many small fibroids can be detected, particularly with transvaginal ultrasound. However, some very small fibroids may not be visible, especially if image quality is affected.
Do all fibroids need treatment?
No. Many fibroids cause no symptoms and do not require treatment. Management depends on symptoms, fibroid size and location, age, reproductive plans, and overall health.
When Should You See a Healthcare Provider?
Arrange a medical evaluation if you experience:
- Heavy or prolonged menstrual bleeding.
- Persistent pelvic pain.
- Pelvic pressure or swelling.
- Frequent urination without infection.
- Difficulty becoming pregnant.
- Bleeding after menopause.
- Rapid enlargement of the abdomen.
Early evaluation helps determine the cause of your symptoms and the most appropriate management.
Conclusion
Ultrasound is an excellent first-line imaging test for detecting uterine fibroids. It can identify the presence, size, number, and location of most fibroids while helping healthcare providers evaluate other pelvic conditions that may produce similar symptoms.
Although ultrasound is highly effective, additional imaging such as MRI may occasionally be required when more detailed assessment is needed. If you are experiencing symptoms suggestive of fibroids, consult a qualified healthcare provider for appropriate evaluation and advice.
Pelvic Ultrasound Services at Omokos Diagnostics
At Omokos Diagnostics, we provide high-quality pelvic ultrasound examinations performed by qualified sonographers using modern ultrasound equipment. Our imaging services help evaluate uterine fibroids, ovarian cysts, pelvic pain, abnormal uterine bleeding, infertility concerns, early pregnancy, and other pelvic conditions.
We are committed to providing accurate ultrasound reports promptly to support healthcare providers in making informed clinical decisions.
Medical Disclaimer
This article is intended for educational and informational purposes only. It should not be considered a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional if you have symptoms such as heavy menstrual bleeding, persistent pelvic pain, abnormal vaginal bleeding, or concerns about uterine fibroids. Never delay seeking medical care based on information you read online.
References
- American College of Obstetricians and Gynecologists (ACOG). Uterine Fibroids (Leiomyomas).
- American Institute of Ultrasound in Medicine (AIUM). Practice Parameter for the Performance of Ultrasound Examinations of the Female Pelvis.
- American College of Radiology (ACR). ACR–AIUM–SPR–SRU Practice Parameter for the Performance of Pelvic Ultrasound Examinations.
- Radiological Society of North America (RSNA) & American College of Radiology. RadiologyInfo.org – Pelvic Ultrasound.
- World Federation for Ultrasound in Medicine and Biology (WFUMB). Guidelines and Recommendations on the Clinical Use of Ultrasound.
- National Institute for Health and Care Excellence (NICE). Heavy Menstrual Bleeding: Assessment and Management.
- Stewart EA, et al. Uterine fibroids. The Lancet. 2017;389(10085):293–308.
