Transvaginal Ultrasound to Diagnose PCOS

transvaginal ultrasound pcos
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Transvaginal ultrasound is one of the main tools a physician has when it comes to diagnosing PCOS. The images found on the ultrasound, in conjunction with the results of blood tests and a thorough patient history and physical, are used to diagnose this syndrome.

Diagnosing PCOS

Characterized by high levels of androgens, (male hormones like testosterone), PCOS is an imbalance of sex hormones. The current diagnostic criteria for women with PCOS states that a woman has PCOS if she has 2 of the following 3 criteria (with exclusion of all other criteria):

1. Absent or irregular menstrual cycles (8 or fewer periods in 1 year)

2. High androgens on blood work or signs of high androgens on the body (acne, excessive hair growth, hair loss)

3. The presence of follicles, commonly referred to as cysts, on an ultrasound. 

Some criteria define PCOS as having 12 or more small follicles in each ovary. However, in the United States, physicians do not typically rely solely on that definition in order to make a diagnosis. There are many women who have cystic ovaries without symptoms of hyperandrogenism, and many women who have been diagnosed with PCOS who do not have classically "cystic" ovaries.

If you are uncertain about your diagnosis of PCOS (or lack of one), it can’t hurt to get a second opinion. Endocrinologists and reproductive endocrinologists are medical specialists with additional training in evaluating and treating hormonal disorders.

Check out the American Society for Reproductive Medicine, or the Androgen Excess and PCOS Society for a local recommendation.

How Is a Transvaginal Ultrasound Performed?

A transvaginal ultrasound can be preformed in a doctor's office. For the procedure, you may be asked to drink up to 42 ounces of fluid before hand to fill the bladder, making it easier to see your ovaries.

 A lubricated ultrasound probe is placed inside the vagina, which transmits an image of the internal organs onto a screen.An ultrasound technician then measures and takes pictures of your ovaries and shares them with your doctor. 

Does Transvaginal Ultrasound Hurt?

Some women may experience very mild discomfort while the technician pushes down during the ultrasound (remember, full bladder!), depending on the ease in which the sonographer can locate the internal reproductive organs.

What Is the Doctor Looking for on the Ultrasound?

The sonographer will examine your uterus, cervix, and uterus. The number of follicles on the ovary will be counted to yield what is known as an antral follicle count.

What Are Antral Follicles?

Antral follicles are resting follicles that are found on the ovary at the beginning of each menstrual cycle. They are approximately 2 to 9 mm in size. A high antral follicle count indicates that a woman has a large number of eggs remaining in her ovary and, in some cases, PCOS.

Cysts vs. Follicles

Both cysts and follicles are common in women with PCOS and those without the condition. Many confuse cysts with follicles.

Despite its name, women with PCOS don't typically produce cysts, but follicles that are used as part of the diagnostic criteria (see below). A name change for PCOS has been proposed to clear up confusion and properly educate health professionals and consumers. 

Women with PCOS tend to produce follicles, which are small collections of fluid in the ovary and are the result, not the cause of, the imbalance of sex hormones.Each month, a woman produces follicles that mature and get released from the ovaries in order to be fertilized. Because of the hormone imbalance, these follicles don't mature and don't get released by the ovaries, causing infertility.

Updated by About PCOS Expert Angela Grassi, MS, RDN, LDN

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