A pelvic ultrasound is one of the most common investigations in gynaecology and fertility care. It's a safe, non-invasive way to examine the uterus, ovaries, and surrounding structures. If you've been referred for a pelvic ultrasound, understanding what to expect and what the scan can show can help reduce any anxiety about the procedure.
What Is a Pelvic Ultrasound?
An ultrasound uses high-frequency sound waves to create images of internal structures. Unlike X-rays, ultrasound doesn't use radiation, making it safe to use repeatedly and during pregnancy. For pelvic imaging, there are two main approaches:
- Transabdominal ultrasound, the probe is placed on your lower abdomen, over a full bladder which acts as a "window" to see the pelvic organs. This provides a broader view.
- Transvaginal ultrasound, a slim probe is gently inserted into the vagina, closer to the organs being examined. This provides more detailed images of the uterus and ovaries.
Often, both techniques are used together to get the most complete picture. In fertility and gynaecology settings, transvaginal ultrasound is typically the primary method due to the clarity of images it provides.
What Does a Pelvic Ultrasound Show?
A pelvic ultrasound allows doctors to examine:
The Uterus
- Size and shape of the uterus
- Position (anteverted, retroverted)
- Endometrial thickness and appearance
- Presence of fibroids (size, number, location)
- Polyps or other abnormalities within the cavity
- Signs of adenomyosis
- Congenital abnormalities (such as uterine septum)
The Ovaries
- Size and appearance of each ovary
- Number of antral follicles (small follicles visible at the start of the cycle)
- Presence of cysts and their characteristics
- Signs suggestive of polycystic ovaries
- Endometriomas (ovarian cysts caused by endometriosis)
Surrounding Structures
- Free fluid in the pelvis
- Fallopian tubes (if abnormally dilated)
- General pelvic anatomy
When Is Pelvic Ultrasound Used?
Pelvic ultrasound is commonly performed to investigate:
- Fertility assessment, examining ovarian reserve, uterine anatomy, and monitoring follicle development during treatment
- Irregular periods, looking for causes such as PCOS or polyps
- Heavy or painful periods, checking for fibroids, adenomyosis, or endometriosis
- Pelvic pain, identifying cysts, fibroids, or other causes
- Abnormal bleeding, assessing the endometrium and uterine cavity
- Suspected ovarian cysts, characterising cysts and monitoring them over time
- IVF monitoring, tracking follicle growth and endometrial development
- Early pregnancy, confirming pregnancy location and viability
What to Expect During the Procedure
Before the scan:
- For transabdominal ultrasound, you'll be asked to have a full bladder
- For transvaginal ultrasound, an empty bladder is preferred
- You may be asked to attend at a particular time in your cycle depending on what's being assessed
During the scan:
- The examination typically takes 15 to 30 minutes
- For transabdominal scanning, gel is applied to your abdomen and the probe moved across your skin
- For transvaginal scanning, a slim probe covered with a disposable cover and gel is gently inserted into the vagina
- You may feel some pressure but it shouldn't be painful, let the sonographer know if you're uncomfortable
- The sonographer will take measurements and images throughout
After the scan:
- Results may be discussed immediately if a doctor performs the scan, or a report sent to your referring doctor
- You can resume normal activities immediately
Understanding Your Results
Ultrasound findings are often reported using specific terminology:
- Antral follicle count (AFC), the number of small follicles visible in the ovaries, which gives an indication of ovarian reserve
- Endometrial thickness, measured in millimetres; varies through the menstrual cycle
- Trilaminar pattern, a healthy three-layered appearance of the endometrium
- Simple cyst, a fluid-filled cyst with thin walls, usually benign
- Complex cyst, a cyst with solid components or irregular features requiring further assessment
- Polycystic ovarian morphology, ovaries containing many small follicles arranged around the periphery
Your doctor will explain what the findings mean in the context of your symptoms and overall health.
Frequently Asked Questions
Is a transvaginal ultrasound painful?
Most women describe it as uncomfortable rather than painful. The probe is slim and inserted gently. If you experience pain, let the sonographer know, they can adjust their technique or pause if needed.
Can I have a pelvic ultrasound during my period?
Yes, although timing may depend on what's being assessed. For fertility scans checking antral follicle count, days 2 to 5 of your cycle are often preferred. For other assessments, timing may be less critical.
What if I've never had a transvaginal ultrasound before?
It's normal to feel nervous. Let the sonographer know, they can explain each step and go slowly. You're in control and can ask them to stop at any time.
Are there any risks with pelvic ultrasound?
Ultrasound is very safe with no known risks. It doesn't use radiation and can be repeated as often as clinically needed.
Need a Pelvic Ultrasound or Results Review?
If you've been experiencing symptoms or have questions about your pelvic ultrasound results, a consultation can help clarify your situation.
Book a Consultation