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The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross. For more articles go to the Medical Library index page.

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a condition characterised by the development of multiple cysts in the ovaries.  It has a range of hormonal and metabolic effects and is a common cause of infertility.
Also known as polycystic ovarian syndrome and Stein-Leventhal syndrome, it is thought PCOS affects up to 10% of all pre-menopausal women. Symptoms can begin to appear in childhood or adolescence, and continue for the entirety of a woman’s life.

While PCOS cannot be cured, it can usually be effectively treated. When left untreated there is an increased risk of high cholesterol levels, type 2 diabetes, cardiovascular disease and endometrial cancer. 

Signs and symptoms

There are a number of symptoms of PCOS which vary in nature and severity from woman to woman. These include: 

  • Irregular periods
  • Excess hair growth (hirsutism) on the face and body
  • Weight gain
  • Acne and oily skin
  • Infertility
  • Hair loss.  


Each month in a healthy ovary an immature egg begins to develop and is released from the ovary when mature. Hormones released by the pituitary gland, luteinizing hormone (LH) and follicle stimulating hormone (FSH) assist in this process known as ovulation.
In PCOS an imbalance of LH and FSH disrupts the ovulation process. As a result, an egg begins to develop but does not fully mature and therefore is not released. Instead, the follicle in which the immature egg is contained becomes a fluid-filled cyst. Each cyst is usually between two to six millimetres in diameter and, over time, multiple cysts can cover the ovary.  As a result, polycystic ovaries can become enlarged.

The cause of PCOS is not fully understood. The condition tends to run in families and a gene influencing the development of the condition has been identified.  It is thought that the following factors also influence its development:

  • Excessive levels of male hormones (androgens) being made in the ovaries
  • A problem with the enzymes involved in male hormone production
  • A problem with insulin metabolism known as insulin resistance (which causes the body to produce excess insulin, which may cause the ovaries to produce too much androgen, which can prevent normal ovulation).  


There is no test to definitively diagnose PCOS.  Diagnosis will involve taking a full medical history and making an assessment of symptoms. Tests used to help diagnose the condition may include:  

  • A pelvic examination in order to determine if the ovaries are enlarged
  • Blood tests to assess hormone, glucose and cholesterol levels
  • An ultrasound scan of the ovaries. 

Note, not all women with PCOS will have polycystic ovaries and not all women with ovarian cysts have PCOS. A diagnosis of PCOS is usually made when there is a combination of two or more of the following: 

  • Irregular periods
  • Increased hair growth or acne, or raised levels of male hormones
  • Appearance of many follicles in the ovaries as seen by ultrasound.  


As PCOS cannot be cured, treatment focuses on managing symptoms. Medications are a mainstay in the treatment of PCOS. The treatment given will depend on the nature and severity of the symptoms.

Insulin resistance:
There is now an understanding that insulin resistance has a large part to play in the development of PCOS. Therefore initial treatment may focus less on the management of individual symptoms and may focus more on correcting insulin resistance. This in turn may improve many other symptoms of the condition. Metformin, which is an oral medication used to treat type 2 diabetes, may be prescribed.  Metformin improves insulin resistance and lowers insulin levels.  It may also help stimulate ovulation and can help with weight reduction when used together with a healthy diet and exercise programme.

Irregular periods:
An oral contraceptive pill may be prescribed to regulate periods.

Excessive hair growth and acne:
These symptoms can be treated with medications that block the action of male hormones. These medications – such as spironolactone and cyproterone acetate - are often referred to as anti-androgens. Some oral contraceptives that contain small levels of anti-androgens may also be used to treat excessive hair growth and acne. Electrolysis or laser hair removal may also be effective for some women.

If infertility is a problem, medications to stimulate the ovaries to produce more eggs, eg: clomiphene citrate, may be prescribed. A surgical procedure called laparoscopic ovarian drilling may be recommended in some cases to improve fertility. During this procedure cysts in the ovaries are cauterised, which can have the effect of stimulating ovulation. This procedure is usually only recommended when all other forms of treatment to increase fertility have been ineffective.

Weight loss:
Weight loss plays an important role in the management of PCOS. Weight loss reduces the amount of male hormones being produced by the body and it can improve the body’s ability to use insulin. Regular exercise and maintaining a healthy balanced diet, that’s low in refined and sugary foods but high in fibre and complex carbohydrates, is also important.

Further information and support

Fertility New Zealand can assist with support and information. They have a number of local societies throughout New Zealand.

Fertility New Zealand
Freephone: 0800 333 306


Lucidi, R.S. (2016). Polycystic ovarian syndrome (Web page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed: 07/07/17]
Mayo Clinic (2014). Polycystic ovary syndrome (PCOS) (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. [Accessed: 07/07/17]
NHS Choices (2016). Polycystic ovarian syndrome (Web Page). Redditch: National Health Service (NHS) England. [Accessed: 07/07/17]
O’Toole, M.T. (Ed.) (2013). Polycystic ovary syndrome (PCOS). Mosby’s Dictionary of Medicine, Nursing & Health Professions (9th ed.). St Louis, MI: Elsevier Mosby.
Last Reviewed – June 2017


Go to our Medical Library Index Page to find information on other medical conditions.