A pelvic ultrasound is the standard first test for pelvic pain, heavy or irregular periods, bleeding after menopause, a suspected cyst or fibroid, fertility questions and early pregnancy. It is also the exam people are most nervous about, because the word “transvaginal” raises obvious questions: Does it hurt? Who is in the room? Can I say no? What if I am on my period?
This guide explains, in order, exactly what happens during both parts of the exam, what the sonographer is looking at and measuring, what the common findings mean, and the choices you have.
Two ways to scan the pelvis
A complete pelvic ultrasound usually has two parts, and understanding why makes the whole thing less mysterious.
- Transabdominal (TA): the probe is moved over your lower abdomen, like any other ultrasound. It gives a wide, overall view of the uterus, ovaries and the space around them, and it can see large fibroids or masses that extend up out of the pelvis. It needs a full bladder, which pushes bowel out of the way and acts as a clear window to look through.
- Transvaginal (TV): a slim probe is placed a short way into the vagina, so that it sits right next to the uterus and ovaries. Because there is almost no tissue in between, the images are far sharper and show fine detail: the lining of the uterus, small cysts or polyps, the ovaries’ follicles, an early pregnancy. It is done with an empty bladder.
Many questions can be answered with the transabdominal part alone. The transvaginal part is added when detail matters, which is most of the time for gynecologic questions and almost always in early pregnancy. If you prefer not to have a transvaginal scan, you can decline it; the sonographer will do the best possible transabdominal study, and the report will simply note that the exam was limited to that approach.
Before you arrive
- Full bladder for the first part. Drink about 32 ounces of water, finishing an hour before your appointment, and don’t empty your bladder. If only a transvaginal scan has been requested, you may be told the opposite; follow the instructions you were given.
- You can be on your period. It does not affect the images, and for some questions (measuring the lining, checking for polyps) scanning in the days right after a period is actually preferred. Bring a pad or tampon to change afterward; the probe cover and gel can be a little messy.
- Wear a two-piece outfit. You will undress from the waist down for the transvaginal part and be given a sheet or gown.
- Bring prior reports if you have had a pelvic ultrasound before. Comparing a cyst or fibroid with an earlier measurement is one of the most useful things the radiologist can do.
- If you want someone with you, a chaperone or a companion, say so. You are always entitled to one for an intimate exam.
What happens, step by step
The transabdominal part (about 10 to 15 minutes)
- You lie on your back on the table with your lower abdomen exposed. The sonographer tucks paper into your waistband to protect your clothes.
- Warm gel goes on your skin, and the probe is moved over the lower abdomen with firm, steady pressure. With a full bladder this can feel like a strong urge to go, which passes as soon as the first part is done.
- The sonographer sweeps through the uterus and both ovaries in two planes, takes measurements, and checks for free fluid.
- You are then sent to empty your bladder completely before the second part.
The transvaginal part (about 10 to 15 minutes)
- You undress from the waist down, lie back with your knees bent, often with a cushion under your hips, and are covered with a sheet.
- The sonographer shows you the probe: it is slim, roughly the width of a tampon applicator, covered with a fresh disposable sheath and lubricating gel.
- The probe is inserted a short way, a couple of inches, and angled gently from side to side and up and down to bring each structure into view. If you would rather insert it yourself, say so; many facilities, including ours, are happy for you to do that.
- You will feel pressure and movement, similar to a pelvic exam or a tampon, and occasionally a brief ache when the probe presses near a tender ovary. Tell the sonographer if anything is painful; they can change the angle or stop.
- Measurements of the uterus, lining and each ovary are taken, Doppler may be used to look at blood flow, and the probe is removed. The whole thing is typically over in ten minutes.
Throughout, the sonographer will explain what they are looking at. What they will not do is give you a diagnosis in the room; a board-certified radiologist reads the images and writes the report (here is why that is the rule).
What the sonographer is measuring
| Structure | What is recorded | Why |
|---|---|---|
| Uterus | Size in three dimensions, position (tilted forward or back), shape, any fibroids with their size and location | Fibroids are extremely common; their position (inside the cavity, in the wall, or on the surface) matters more than their presence. |
| Endometrium (the lining) | Its thickness in millimeters and appearance | The normal thickness changes through the cycle (thin after a period, thick before it) and is thin after menopause. The number is always interpreted against where you are in your cycle or whether you are postmenopausal; the same measurement can be normal in one situation and worth checking in another. |
| Ovaries | Size and volume, follicles, any cysts with their size and features | Small fluid-filled follicles are normal and change every month. A simple cyst up to about 3 cm in a woman who is still cycling is usually just that month’s follicle and often needs no follow-up. |
| Adnexa (around the ovaries) | Anything beside the ovaries: fluid in a tube, masses | Most adnexal findings are benign; features are scored with the O-RADS system when needed. |
| Pelvic free fluid | Present or not, and how much | A small amount is normal, especially mid-cycle after ovulation. |
| IUD | Whether it is present and in the right position | A quick check that it sits where it should. |
Common findings and what they usually mean
- Simple ovarian cyst. A thin-walled sac of fluid. In premenopausal women, small ones are normal physiology; larger ones are often rechecked after a cycle or two to confirm they have resolved.
- Hemorrhagic cyst. A follicle that bled into itself; it can cause sudden pain and looks complex on the scan, but typically resolves on its own within a few weeks.
- Endometrioma. A cyst with a characteristic “ground glass” appearance linked to endometriosis.
- Dermoid. A benign cyst containing fat and other tissue, with a distinctive appearance.
- Fibroids. Benign muscle growths in the uterine wall, present in a large proportion of women by their 40s. The report notes size and location; many need no treatment.
- Adenomyosis. Lining tissue within the muscle wall, which makes the uterus look thickened and heterogeneous; a common cause of heavy, painful periods.
- Endometrial polyp. A small growth from the lining, usually seen best just after a period; sometimes confirmed with a saline-infusion scan.
- Polycystic-appearing ovaries. Enlarged ovaries with many small follicles. This is an appearance, not a diagnosis; polycystic ovary syndrome is diagnosed from symptoms and blood work as well.
- Hydrosalpinx. A fluid-filled, blocked fallopian tube.
- Thickened endometrium after menopause. Particularly with bleeding, this prompts further evaluation by your gynecologist; a thin lining in that setting is reassuring.
Most of these are benign. Our guide to ultrasound report terms explains the vocabulary, and the O-RADS section there covers how ovarian findings are categorized.
Your choices, and who should not have a transvaginal scan
- You can decline the transvaginal portion at any point, before or during, and the exam will continue transabdominally.
- You can ask for a chaperone, bring a companion, or ask to insert the probe yourself.
- If you have never been sexually active, have vaginal pain conditions, or are recovering from surgery, tell the sonographer; a transabdominal-only exam, sometimes with a slightly fuller bladder, is the usual alternative.
- For patients under 18, UltraVision Imaging performs transabdominal pelvic ultrasound only.
- Transvaginal ultrasound is routinely and safely performed in early pregnancy; it does not cause miscarriage.
After the scan
There is nothing to recover from. You may have a little gel to wipe away and, if you were on your period, some light spotting from the probe. The images go to the radiologist, and at UltraVision Imaging the written report is typically ready within 24 hours, for you and, if you like, your gynecologist or primary care physician.
Booking a pelvic ultrasound
Pelvic ultrasound, transabdominal alone or combined with transvaginal, can be booked directly at UltraVision Imaging without a referral, at our private clinic or as a home visit. Every study is performed by an ARDMS-certified sonographer and read by a board-certified radiologist. Enter your ZIP to see times, or call (916) 751-1944 if you would like to talk through the exam first. Sudden, severe pelvic pain, heavy bleeding, or pain with fever should be evaluated urgently by your doctor or an emergency room rather than booked as a routine scan.
Frequently asked questions
Does a transvaginal ultrasound hurt?
For most people it causes pressure rather than pain, similar to a pelvic exam or inserting a tampon. The probe is slim, covered with a fresh sheath and gel, and inserted only a short way. Tell the sonographer if anything hurts; they can change the angle or stop, and you can decline the transvaginal portion at any time.
Can I have a pelvic ultrasound on my period?
Yes. Menstruation does not affect the images, and for some questions, such as measuring the lining or looking for polyps, scanning in the days just after a period is preferred. Bring a fresh pad or tampon for afterward.
Why do I need a full bladder for a pelvic ultrasound?
A full bladder pushes bowel out of the pelvis and acts as a clear fluid window for the transabdominal part of the exam. You will be asked to empty it before any transvaginal portion, which works best with an empty bladder.
How long does a pelvic ultrasound take?
About 10 to 15 minutes for the transabdominal part and another 10 to 15 for the transvaginal part. Appointment slots are longer to allow for check-in and positioning.
Can I refuse the transvaginal part?
Yes. The exam will continue transabdominally, and the report will note that it was limited to that approach. You can also ask for a chaperone, bring a companion, or insert the probe yourself.
Is a transvaginal ultrasound safe in early pregnancy?
Yes. It is the standard way to confirm and date an early pregnancy, has no known harmful effects, and does not cause miscarriage.
What does a pelvic ultrasound show?
The size, shape and position of the uterus; the thickness and appearance of the lining; the ovaries and any follicles or cysts; the areas beside the ovaries; free fluid; and the position of an IUD. Common findings include fibroids, simple cysts, endometriomas, polyps and adenomyosis, most of which are benign.
Do I need a referral for a pelvic ultrasound?
Not at UltraVision Imaging. Transabdominal and transvaginal pelvic ultrasound can be booked directly, and the radiologist’s report is typically ready within 24 hours.
This article is general health information, not medical advice. It does not replace a conversation with your own physician, who knows your history and can interpret results in context. If you have symptoms that worry you, contact your doctor; if you think you are having a medical emergency, call 911.