Definition of PCOS

Polycystic ovary syndrome (PCOS) is a hormonal disorder which was first described by doctors in the 1930s. It is sometimes referred to as "hyperandrogen anovulation syndrome" or "Stein Leventhal Syndrome".

If you have PCOS you may have symptoms such as:

• Periods that are irregular, infrequent or heavy
• Difficulty in becoming pregnant
• Immature ovarian eggs that do not ovulate, forming small follicles. Follicles are small fluid filled sacs on the ovaries.
• Weight gain and an increase in fat, especially around the abdomen or tummy area
• Excessive facial or body hair
• Acne on both the face and the body
• Prediabetes or diabetes
• Higher levels of blood fats

How common is PCOS?

Studies from Australia and overseas show that up to 10 per cent of all women of reproductive age (post puberty and pre-menopausal) have PCOS.

What causes PCOS?

The cause of PCOS is unknown. There appears to be a contribution from a woman's genetics (i.e. a hereditary component passed down through their family) and from her lifestyle or environment.  (For more information see Causes)

Polycystic ovaries

The name of the condition PCOS (polycystic ovary syndrome) implies that all women with PCOS have polycystic ovaries . However, having polycystic ovaries on ultrasound is not essential for the diagnosis of PCOS. Approximately 75 per cent of women with PCOS have polycystic ovaries on ultrasound.

While up to 10 per cent of women of reproductive age have PCOS, the syndrome, up to 25 per cent of women of reproductive age can have polycystic ovaries on ultrasound. These women either have no other symptoms of PCOS or have very mild symptoms and are therefore not classified as having the ‘syndrome' called PCOS.

We are looking for both women with PCOS and women without PCOS but who have polycystic ovaries on ultrasound for a research project assessing risk factors for diabetes and cardiovascular disease. For more information see 'Assessing diabetes and CVD risk'.

While it is thought that women with polycystic ovaries (but not PCOS) do not have increased infertility, it is not clear if they have a higher risk for metabolic disease (diabetes and heart disease) than women without polycystic ovaries. There is some evidence that women with type 2 diabetes or previous gestational diabetes (diabetes in pregnancy) have a higher rate of polycystic ovaries. Other research has shown lower ‘good' cholesterol (high density lipoprotein cholesterol), higher markers of inflammation (an early sign of heart disease) and worse blood vessel function in women with polycystic ovaries compared to women without polycystic ovaries. However, a number of other research studies have shown no differences in risk factors for heart disease and diabetes such as glucose and insulin resistance between women with polycystic ovaries (but not PCOS) and women without polycystic ovaries.

A sensible approach, if you have polycystic ovaries but not PCOS, would be to follow a healthy lifestyle and maintain a healthy weight with good dietary and exercise practices to reduce potential long-term risks of diabetes and heart disease.

Content updated July 31, 2009