Women’s Health · The Examination

The Transvaginal Ultrasound Scan — What to Expect

Why it is recommended, what it shows that an abdominal scan cannot, what actually happens in the room — and the honest answers to the questions people find hardest to ask.

A sonographer is getting ready to perform a transvaginal scan on a woman lying on her back with her knees bend

A transvaginal ultrasound — often shortened to TVS, and sometimes called an internal scan — uses a slim probe placed in the vagina to examine the uterus, endometrium, ovaries and surrounding structures. The reason it is used is simple physics: the probe sits close to the organs being examined, so the images are considerably clearer than scanning through the abdominal wall. That clarity is what allows a small ovarian cyst to be characterised, an endometrial thickness to be measured accurately, or an early pregnancy to be located.

Most people approach it with some apprehension, and that is entirely reasonable. What follows is the practical detail — including the parts about consent, control and declining — because knowing exactly what will happen is what makes it manageable.

Seek urgent medical care rather than booking if you have

Sudden severe pelvic pain, especially with dizziness or faintness · heavy vaginal bleeding beyond a normal period · fever alongside pelvic pain · sudden abdominal swelling or tenderness. These can indicate an ectopic pregnancy, ovarian torsion or acute pelvic infection — go to A&E or call 999. A booked scan is not the right route for any of them.

Why This Scan

What it shows that an abdominal scan cannot

Both approaches examine the same organs; the difference is resolution. Scanning through the abdomen means sound travels through skin, fat and muscle before reaching the uterus, and it needs a full bladder to push the bowel out of the way. A transvaginal probe starts a few centimetres from the target, uses a higher frequency, and needs an empty bladder.

In practice that means transvaginal scanning is preferred for: early pregnancy, where it detects a sac and heartbeat one to two weeks sooner; endometrial thickness, where millimetres matter and are read against your cycle or menopausal status; ovarian assessment, including characterising cysts and counting follicles; and investigating pelvic pain or abnormal bleeding, where small findings change the answer. Our guide to transabdominal versus transvaginal scanning compares the two in more depth, and understanding your pelvic report explains the measurements either approach produces.

In The Room

What actually happens

  1. 1
    Before you startYou empty your bladder — the opposite of an abdominal pelvic scan. The examination is explained, you can ask anything, and nothing proceeds until you agree to it. You undress from the waist down in private and are given a sheet; a chaperone can be present, and you are welcome to bring someone with you.
  2. 2
    PositionYou lie on your back with knees bent and apart, sometimes with a cushion under the hips. You are covered throughout except where the probe is inserted.
  3. 3
    The probeSlimmer than a tampon applicator, covered with a single-use protective sheath and lubricating gel, and inserted only a short distance — roughly 5 to 8cm. It does not enter the cervix or the womb. Many people prefer to insert it themselves, and that is always an option.
  4. 4
    The examinationThe probe is angled gently to view the uterus and each ovary in turn, which takes about 10 to 15 minutes of a 30-minute appointment. You may feel pressure; it should not be painful. Say so at any point and the scan pauses or stops — that is not an inconvenience, it is how it should work.
  5. 5
    AfterwardsYou dress in private and resume your day immediately. Findings are explained to you on screen, and a written report follows — usually within two hours — phrased for your GP to act on.

Our first-time guide covers the experience in more personal detail if this is your first internal scan.

The Harder Questions

Things people find difficult to ask

Can I say no? Yes, at any point, including after the scan has started. A transabdominal scan can be performed instead — it sees less detail, and an honest report will say what could not be assessed, but it remains a legitimate choice and nobody should make you feel awkward about it.

What if I have never been sexually active? Transvaginal scanning is not routinely performed in this situation, and you should not be pressured into it. Say so when booking or on arrival and an abdominal approach is used instead.

Can I have it during my period? Yes — it is safe and often perfectly practical, and sometimes specific cycle timing is exactly what is needed. Tell us when you book; if timing matters clinically we will say so. Bleeding does not make the scan unhygienic or embarrassing to us; it is routine.

Does it hurt? It should not. Most people describe pressure rather than pain. Conditions such as endometriosis or infection can make the pelvis tender, so tell us beforehand and the examination is adapted.

Can it cause a miscarriage or harm a pregnancy? No. The probe enters the vagina only — not the cervix, not the womb — and does not touch the pregnancy. Diagnostic ultrasound is not known to cause miscarriage. Light spotting afterwards can happen because the cervix is more delicate in pregnancy, and it is not a sign of harm; our guide to ultrasound safety sets out the evidence.

FAQs

Your questions answered

Do I need a full bladder for a transvaginal scan?
No — the opposite. An empty bladder is more comfortable and gives a better view. A full bladder is needed for abdominal pelvic scanning, which is why the two instructions differ and are easy to confuse.
How far does the probe go in?
Only a short distance, roughly 5 to 8cm — comparable to inserting a tampon. It does not pass through the cervix or reach the womb, and it is covered by a single-use sheath with lubricating gel.
Is a transvaginal scan painful?
It should not be. Most people report pressure rather than pain. If your pelvis is already tender — from endometriosis, infection or another cause — say so beforehand, and tell us at any point during the scan so it can be adapted or stopped.
Can I refuse and have an abdominal scan instead?
Yes, always. An abdominal scan sees less detail, and the report will state honestly what could not be assessed, but it is a legitimate alternative and your consent is required throughout.
Can I have the scan on my period?
Yes — it is safe and routine, and for some questions a specific point in the cycle is actually preferred. Mention it when booking so timing can be advised if it matters clinically.
Can I bring someone with me, or have a chaperone?
Both. You may bring a friend or family member, and a chaperone can be present for the examination. Ask at booking or on arrival — it is a normal request, not an unusual one.
Why is a transvaginal scan better in early pregnancy?
Because it sees detail one to two weeks earlier than abdominal scanning. At six or seven weeks an abdominal scan may show very little even in a healthy pregnancy, which is why internal scanning is standard at that stage.
Related

Where to go from here

First TimeYour First Internal Scan

The experience in personal detail, for anyone feeling apprehensive.

Read the guide →Your ReportYour Pelvic Report Explained

Endometrial thickness, ovarian volume, follicles and free fluid decoded.

Read the guide →£159Pelvic Ultrasound Scan

The examination itself — what it covers and how to book.

About the scan →

Scanned by people who explain first

HCPC-registered sonographers, consent and comfort taken seriously, findings shown to you on screen, and a written report usually within two hours for your GP.

£159
Pelvic ultrasound scan

Book a Scan

5a Lucerne Mews
Kensington, London W8 4ED
3 mins from Notting Hill Gate

This article is general information, not individual medical advice. Consent to any intimate examination is yours to give or withhold at any point, and an alternative approach is always available. If in doubt about a symptom, speak to your GP or call NHS 111.

Written and clinically reviewed by the HCPC-registered sonographers who perform this scan at IUS London — a CQC-registered diagnostic ultrasound clinic (Provider ID 1-2775844974). Your own findings are explained to you at the scan and set out in your report.

Author: Yianni Kiromitis, Senior Sonographer, HCPC RA38415
Medically reviewed: 1 August 2026