Transvaginal ultrasound: preparation, procedure, advantages and disadvantages

By Cristiano Antonino On Nov 7, 2022

Transvaginal ultrasound or ‘trans-vaginal ultrasound’, sometimes abbreviated to ECO-TV or ETV or TVS (from ‘Trans-Vaginal Sonography’) or TVU (from ‘Trans-Vaginal Ultrasonography’) is a diagnostic imaging technique that investigates the morphology and health status of the female internal genitalia using a high-frequency ultrasound probe that is introduced into the vagina

Transvaginal ultrasound is performed by a gynaecologist or other competent medical personnel.

Transvaginal ultrasound is performed in three main cases

suspicion of pathologies affecting the female genital apparatus
early visualisation of the gestational chamber in patients with suspected pregnancy;
obstetric assessment of cervical length and evaluation of possible funneling.

Which pathologies does it investigate?

The high frequency of the probe allows a high resolving power that enables the observation and measurement of various pathologies and conditions, including:

extrauterine pregnancy
adenomyosis and endometriosis;
malformations;
ovarian masses and other pathological conditions of the adnexa (e.g. cysts, PCOS…);
abscesses or localised infectious processes;
endometrial hyperplasia;
uterine leiomyomatosis;
cervical-endometrial neoplasms (cancer);
infertility or sterility;
endometrial or cervical polyps.

Advantages of transvaginal ultrasound

Trans-vaginal ultrasound, thanks to the use of a high-frequency probe, makes it possible to investigate the uterus, ovaries and adnexa in detail, as well as to monitor pregnancy in the first trimester or as part of assisted reproduction techniques.

Compared to transabdominal pelvic ultrasound (in which the ultrasound probe is placed on the lower abdomen), it allows better visualisation of the uterus, endometrium, cervix, fallopian tubes, ovaries and the parauterine space, including the parieto-colic loggias and the Douglas cavity.

This greater precision and detail is given by the proximity of the ultrasound probe to the structures to be examined and the absence of the ‘shield’ represented by the organs and tissues that inevitably encounter the ultrasound in the trans-abdominal route (in particular the bladder and adipose tissue, especially if the woman is severely obese).

Compared to investigations performed with X-rays or CT scans, trans-vaginal ultrasound does NOT use ionising radiation, so it can be performed several times safely and even in pregnant women without danger to the foetus.

Disadvantages of transvaginal ultrasound

Compared to transabdominal pelvic ultrasound, transvaginal ultrasound is certainly more invasive, more bothersome and more risky.

It is also generally more expensive than transabdominal pelvic ultrasound.

It cannot be performed in virgin women (with intact and not particularly elastic hymen).

It is an operator-dependent technique: its ability to detect pathology is strongly dependent on the experience of the physician performing it.

Preparation for the examination

The patient is asked to urinate before the examination and, once the bladder is empty, is made to undress from the waist down and lie on an examination couch in the gynaecological position.

Sometimes, however, it is required to have a full bladder (drinking and not urinating in the hour before the examination) in order to also perform the external pelvic ultrasound.

Transvaginal ultrasound, the procedure

Trans-vaginal ultrasound is considered a moderately invasive method; whereas in traditional trans-abdominal ultrasound the probe is placed on the lower abdomen, in trans-abdominal ultrasound the probe is placed inside the vagina.

This probe has a high frequency, is long and narrow, is covered with disposable material (similar to a condom) and is small (just over 1 cm in diameter).

The probe is inserted more easily into the vagina thanks to the ultrasonography gel, allowing easy and painless entry.

How long does it last?

The examination is generally completed in 10 to 15 minutes, except in cases where abnormalities are detected that may require more time to be analysed.

What to do at the end of the examination?

At the end of the examination you can return to normal daily and work activities.

There is no need to be accompanied by other people, as you are self-sufficient at the end of the examination.

After the examination you can safely drive and handle dangerous instruments and vehicles, as the examination does not induce drowsiness.

Is transvaginal ultrasound painful?

The examination is not painful, however it is considered unpleasant by many patients.

You may feel discomfort and pressure especially during the penetration of the probe.

Is the examination risky?

The examination, using ultrasound, is not risky for the woman’s health, nor for that of the possible foetus.

In very rare cases, the probe may lead to lesions inside the vagina.

Contraindications

The examination has no particular contraindications.

It cannot be performed in virgins (with intact, inelastic hymen) who wish to preserve the integrity of the hymen.

Can transvaginal ultrasound be performed on a virgin woman?

In virgin women, with intact hymen, the examination cannot be performed, except in those cases where the intact hymen is still sufficiently elastic to allow the test to be performed.

It is the doctor who decides whether or not to perform the examination.

Can transvaginal ultrasound be performed during menstruation?

The investigation can be performed at any stage of the menstrual cycle and – if urgently needed – also during menstruation, however, it should preferably not be performed during menstruation.