Polycystic Ovary Syndrome Ultrasound

Polycystic ovary syndrome (PCOS) affects 6%–12% of women of reproductive age in the US (approximately 5 million), making it one of the most common causes of female infertility. PCOS has various symptoms, contributing factors, and severe health consequences, including infertility, cerebral vascular disease, and coronary artery disease.¹

Diagnostic testing can include ultrasound, pelvic exams, and blood tests. Read on to understand PCOS and discover why ultrasound can offer a reliable diagnosis.

Have you considered clinical trials for Polycystic ovarian syndrome (PCOS)?

We make it easy for you to participate in a clinical trial for Polycystic ovarian syndrome (PCOS), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is PCOS?

PCOS is a hormonal condition that affects women during their childbearing years. It can also stop a woman's periods or cause them to be irregular.

Some PCOS patients may develop cysts on their ovaries, hence the term “polycystic.” PCOS tends to affect a woman's ovaries — the reproductive organs that produce most of a woman’s estrogen and progesterone, hormones that regulate the menstrual cycle.

Unfortunately, most women with PCOS aren't aware of its existence. Being on the lookout for PCOS symptoms and visiting the doctor for routine checkups can help detect and treat the condition in its early stages.

Symptoms of PCOS

PCOS symptoms include:

  • Infertility

  • Weight gain

  • Mood changes

  • Acne or oily skin

  • Darkened skin or excess skin in the armpits or on the neck

  • Hirsutism — excess hair growth on the face, back, stomach, or chest

  • Irregular periods/missed periods/light periods

  • Male-pattern baldness or thinning hair

  • Weight gain — a large percentage of women with PCOS are overweight or obese

  • Hormonal changes can also trigger headaches in some women

Causes of PCOS

There is no known definitive cause of PCOS. However, doctors believe that high male hormone levels prevent the ovaries from producing hormones and eggs normally. Furthermore, doctors advise women to watch out for the following risk factors that increase their likelihood of developing PCOS.


PCOS can sometimes run in the family. If any of your female relatives, such as your mother, aunt, or sister, have PCOS, your risk of developing PCOS is higher. Specific genes related to the condition haven't been identified yet.


Women with PCOS typically have increased inflammation levels. Obesity is a contributing factor to inflammation. Studies have also linked inflammation to increased androgen levels.²

Insulin resistance

Up to 70% of women diagnosed with PCOS have insulin resistance, so their cells don’t respond properly to insulin. This causes an increase in demand for insulin, leading to the pancreas producing more insulin to overcompensate.

Unfortunately, excess insulin triggers the ovaries to produce more male hormones, increasing the risk of PCOS. Insulin is often a result of obesity. Consequently, insulin resistance and obesity can increase one's risk for type 2 diabetes.

How does an ultrasound diagnose PCOS?

When you visit your doctor, they will likely discuss your symptoms, medications, and underlying medical conditions. They may also ask about any weight changes and your periods.

Your doctor may conduct a physical exam to check for signs of excess hair growth, acne, and insulin resistance. They may recommend that you have an ultrasound.

An ultrasound checks and assesses the appearance of your ovaries and the thickness of your uterus lining.

Ultrasounds can be either transvaginal or abdominal. Both are painless tests with no radiation.

Transvaginal ultrasound

The doctor places a wand-like device (transducer) in your vagina. This device emits sound waves that translate into images on a computer screen. A transvaginal ultrasound may obtain more direct imaging to help in diagnosis.

Abdominal ultrasound

A trained caregiver uses a special gel and an ultrasound device to view the ovaries from the skin surface of your abdominal area.

What does PCOS look like in an ultrasound?

To properly diagnose PCOS, certain criteria must be seen on ultrasound. According to experts, only one ovary needs to be polycystic for a PCOS diagnosis.³

For an ovary to be polycystic, it will have at least one of the following two characteristics:

  • Increased ovarian volume of more than 10 cm

  • The presence of 12 or more ovarian/antral follicles (measuring 2–9 mm) arranged peripherally in the ovary like a pearl string

What do doctors look for in an ultrasound?

The sonographer examines your cervix and uterus to count and determine the number of follicles on your ovary to arrive at an antral follicle count. Antral follicles are resting follicles found in the ovary at the start of each menstrual cycle. A high antral follicle count means you have many eggs remaining, which could signify PCOS.

The doctor will use ultrasound to identify and detect changes in the appearance of tissues, organs, and vessels. They will also use ultrasound to detect abnormal masses, such as tumors.

In a transvaginal ultrasound, the transducer sends sound waves and records the returning (echoing) waves. When pressed against the skin, the transducer sends small pulses of inaudible, high-frequency sound waves into your body.

While the sound waves bounce off the internal organs, tissues, and fluids, the transducer's sensitive receiver records tiny changes in the waves’ direction and pitch. A computer then measures these waves and displays them as real-time pictures on the monitor to arrive at a diagnosis.

How else can PCOS be diagnosed?

Besides an ultrasound, your doctor may recommend:

  • A blood test: The blood test will be used to measure hormone levels, and it can exclude possible causes of menstrual problems or excess androgen-mimicking PCOS. The doctor can also conduct other blood tests, such as fasting triglyceride levels.

  • A pelvic exam: The care provider will check your reproductive organs for masses, growth, or any other changes.

The lowdown

PCOS is a hormonal condition that affects many women in several ways, including infertility. Though there is no precise known cause of PCOS, high male hormone levels are often associated with the condition.

Fortunately, diagnosis options such as ultrasound and blood tests can help determine the presence and extent of PCOS.

Most women don't know they have PCOS until the symptoms manifest in full force. Therefore, ensure you visit your doctor if you notice any of the PCOS symptoms mentioned in the article, such as irregular menstrual cycles, mood changes, and excessive weight gain.

Frequently asked questions

What is the follicle size for PCOS?

The antral/ovarian follicle measures 2–9mm. The size differs at different stages.

Does PCOS affect follicle count?

Yes, it does. In PCOS, abnormal hormone levels hinder the growth and maturation of follicles that play a vital role in the release of egg cells. The immature follicles accumulate in the ovaries, with affected women having 12 or more of these follicles.

What are follicles in PCOS?

Follicles are the underdeveloped sacs in which the eggs develop and mature. In PCOS, these sacs typically can't release an egg, so ovulation doesn’t occur.

Can PCOS have a dominant follicle?

No, the characteristic feature of polycystic ovaries is an apparent failure to choose a dominant follicle, resulting in antral follicle accumulation.

What do PCOS follicles look like?

PCOS is characterized by many follicles developing simultaneously — typically more than 12 arranged in a circle — with a pearl-string appearance. Furthermore, polycystic ovaries tend to be large with a slightly different appearance from regular ovaries.

What confirms a PCOS diagnosis?

The confirmation of a PCOS diagnosis requires two of the following criteria:

  • Multiple small cysts on the ovaries

  • A sign of increased androgen levels or a blood test confirming increased androgen levels

  • Irregular ovulation, often indicated by an irregular menstrual cycle or the lack of a cycle

Are polycystic ovaries serious?

Yes, polycystic ovaries can lead to further complications, such as:

  • High blood pressure

  • Type 2 diabetes

  • Infertility

  • Uterine cancer

  • Heart and blood vessel problems

Do polycystic ovaries need to be removed?

No. However, ovarian surgery can be the only treatment solution if other treatment attempts don't work. These include birth control pills, weight loss, and spironolactone (diuretic medication).

What causes PCOS belly?

High androgen levels trigger symptoms such as excessive body hair growth, irregular periods, and weight gain. Since male hormones trigger this weight gain, this weight increase is usually in the abdomen.

Can you see PCOS on an ultrasound?

Not directly, although an ultrasound can help you determine the presence of PCOS.

Is it normal to have polycystic ovaries?

Having polycystic ovaries isn't normal. However, PCOS is a common hormonal problem that affects one in ten women of childbearing age.

Have you considered clinical trials for Polycystic ovarian syndrome (PCOS)?

We make it easy for you to participate in a clinical trial for Polycystic ovarian syndrome (PCOS), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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