Transvaginal Ultrasound

Why we explain this on a separate page

The abdominal ultrasound uses the bladder as a window. The transvaginal scan takes the bladder out of the way and brings the probe close to the target. Same machine, different question. A thin endometrium, an early sac, a small ovarian cyst and the position of an IUD need this closeness. The second-trimester anatomy scan and baby measurements in late pregnancy, on the other hand, are done through the abdomen. Merging the two under one heading gives the patient the wrong preparation: one needs a full bladder, the other an empty one.

When it is considered

A transvaginal scan is not required at every gynaecological visit. A smear, a discharge sample and the examination are separate tasks. Ultrasound does not replace cells.

How the scan is done

The patient lies on her back with her knees bent. The bladder has been emptied. The probe is covered with a single-use cover or sheath and gel is applied. AIUM states that the probe may be inserted by the patient, the sonographer or the physician, preferably with the screen on. At SoftCare the insertion is explained, and if the patient wishes she makes the first advance herself. A chaperone stays in the room according to clinic routine and the patient's wishes.

The probe rests against the upper part of the vagina. It does not pierce the cervix and does not enter the uterus. To obtain images it is gently turned left and right. This turning is not a speculum examination. Most scans take a few minutes. The pressure is different from that of a full bladder; most women describe fullness rather than pain. If there is pain, the scan is stopped.

A bleeding day is not an obstacle. Light spotting does not soil the probe; the cover is changed. If there is heavy bleeding and fainting, blood pressure and the location of the pregnancy are discussed first; it is not left to wait as an “appointment ultrasound”.

Consent and when it is not done

A transvaginal ultrasound is not started on its own as though it were part of the examination. What it is, why it is requested and the right to refuse are explained. If the patient does not want it, it is not done. This refusal is recorded in the file as an incomplete view; it is not a choice to be scolded for.

Vaginismus, recent surgery, severe pain and the patient saying “I do not want this scan” stop the procedure. A transvaginal probe is not routine in a woman who says she is a virgin. An abdominal scan and, if needed, another day and another method for a question the abdominal view cannot answer are discussed. Forcing it also spoils the image quality.

Pregnancy is not an obstacle to a transvaginal scan. If the location is in doubt in early weeks, this route leaves less uncertainty. The probe does not cause miscarriage. In a woman with threatened miscarriage the scan is done to see where the sac is, not to increase bleeding.

What is asked in early pregnancy

The first question is whether the sac is in the uterus. If the uterus is empty, the test is positive and there is pain, ectopic pregnancy is not considered ruled out. The number of days the period is late is more useful than a single measurement. Very early on, the sac may not be visible; this does not mean “there is none”. The course of the blood hormone and a second scan stay in the same file.

Once the heartbeat is seen, the crown-rump length roughly gives the week. If it does not match the last period, it is the doctor who decides which date to go by. Twins, an empty sac and suspected miscarriage are not declared from a single image. The yolk sac and the embryo are looked for separately. Late-pregnancy measurements described on the abdominal ultrasound page are not repeated here.

Uterine lining and IUD

The endometrium changes with the cycle. It is thin just after a period and thickens towards ovulation. A single millimetre is not a disease. In postmenopausal bleeding, a thin, regular lining may allow the decision to take a sample to be postponed. With a thick, irregular or fluid-filled lining, a biopsy or hysteroscopy is discussed. The threshold depends on whether there is bleeding and on how clear the measurement is; the same millimetre is not written for every woman.

The body of the IUD should sit in the cavity with the arms open to the sides. An image of an IUD that has slipped down or is embedded in the myometrium is read together with pain and bleeding. An IUD is not considered expelled just because the strings cannot be seen; the transvaginal scan looks for the IUD, not for the strings.

Ovaries and fluid

An ovary can be hidden among the bowel loops. The transvaginal scan shows most of it more closely than an abdominal scan; even so, both ovaries may not be visible in every woman. A simple small cyst is usually monitored. A haemorrhagic cyst, a chocolate-cyst appearance and torsion with sudden pain are separate matters. Torsion is not diagnosed from the image alone.

A little fluid in the pouch of Douglas can be normal around ovulation. Excess fluid, fever and pain that increases with movement suggest infection. Ultrasound does not replace a culture.

What it does not show

It does not replace a smear, HPV testing or a cervical biopsy. It does not report whether the tubes are open. It often misses superficial endometriosis. It cannot certify from the image that a fibroid is benign. It does not close the question of ectopic pregnancy as “none”. It does not produce a hormone panel. Doppler is not added to every scan.

Preparation

If possible, empty your bladder before the scan. No fasting is needed. A skirt or lower clothing that is easy to take off is enough. Avoiding sex beforehand is not routine. Vaginal bleeding is not an obstacle. If the probe cover is latex, mention a latex allergy at the start.

Our approach at SoftCare

A transvaginal ultrasound is not a continuation of the abdominal ultrasound page. The reason it is requested is explained; if it is refused, it is not done. The probe is covered with a single-use sheath for each woman and does not enter the uterus. Location in early pregnancy, the uterine lining in bleeding, the position of an IUD and the ovaries are the work of this scan. A smear and a culture are separate doors. The measurement is written down; the decision is made in the consultation room.

Listing these sources does not mean SoftCare wrote those texts. The abdominal ultrasound is covered on a separate page.

Medically reviewed by Op. Dr. Şükrü Sanus, Obstetrician & Gynecologist · Last medical review: 2 October 2026