Southern Cross Medical Library

Southern Cross Medical Library

Polycystic ovary syndrome (PCOS) is a condition related to elevated levels of certain hormones, causing the development of cysts in the ovaries. The condition can have a range of impacts on a woman’s health and fertility.

Also known as polycystic ovarian syndrome and Stein-Leventhal syndrome, it is thought that PCOS affects up to 10% of all pre-menopausal women. Symptoms can first appear in childhood or adolescence and continue for the entirety of a woman’s life.

While PCOS cannot be cured, its effects on the body can be controlled. When left untreated, there is an increased risk of many other conditions, including high cholesterol levels, type 2 diabetes, gestational diabetes, cardiovascular disease, sleep apnoea, depression, and endometrial cancer.

Signs and symptoms

Symptoms of PCOS vary in nature and severity and may include:

  • Irregular periods
  • Excess hair growth (hirsutism) on the face and body
  • Acne and oily skin
  • Infertility
  • Thinning or hair loss on the top of the head
  • Weight gain or obesity.


Each month in a healthy ovary, an immature egg begins to develop and is released from the ovary when mature. In PCOS, an imbalance of certain hormones disrupts this 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:

  • Higher than normal levels of male hormones (testosterone) being made in the ovaries
  • A problem with insulin metabolism known as insulin resistance, which causes the body to produce more insulin. Excess insulin may cause the ovaries to produce too much testosterone, which can prevent normal ovulation.


There is no test to definitively diagnose PCOS. Diagnosis involves taking a full medical history and assessing symptoms. Tests used to help diagnose the condition may include:

  • A pelvic examination to determine if the ovaries are enlarged.
  • Blood tests to measure 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.

Lifestyle changes:

Weight loss achieved through making lifestyle changes, including a low-calorie, high-fibre diet and a moderate increase in exercise levels, is the first line of treatment for PCOS. Weight loss reduces the levels of male hormones being produced by the body and improves the body’s ability to use insulin. Even a modest reduction in weight, losing just 5% of body weight, can result in a reduced risk of type 2 diabetes and a marked improvement in PCOS.

Insulin resistance:

Insulin resistance plays a role in the development of PCOS. Therefore, initial treatment may involve medications for 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 loss when used together with a healthy diet and exercise programme.

Irregular periods:

An oral contraceptive pill may be prescribed to regulate periods. Combination oral contraceptive pills that contain oestrogen and progestin reduce male hormone production and control oestrogen levels, which helps to regulate periods and lower the risk of endometrial cancer. Another option is taking a course of progestin-only tablets every one or two months, which also helps to regulate periods and reduce the risk of endometrial cancer.

Excessive hair growth and acne:

These symptoms can be treated with medications that block the action of male hormones. Combined oral contraceptives can 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 (destroyed with heat), 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.

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

E-mail: [email protected]



Lucidi, R.S. (2019). Polycystic ovarian syndrome (Web page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed: 31/03/20]
Mayo Clinic (2017). Polycystic ovary syndrome (PCOS) (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. [Accessed: 31/03/20]
NHS Choices (2019). Polycystic ovarian syndrome (Web Page). Redditch: National Health Service (NHS) England. [Accessed: 31/03/20]
O’Toole, M.T. (Ed.) (2017). Polycystic ovary syndrome (PCOS). Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.

Last reviewed – April 2020

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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.