What is Polycystic ovary syndrome
It is common for women to have polycystic ovaries, which means their ovaries develop more follicles than normal every month. Usually about five follicles start to mature during each menstrual cycle and at least one egg-containing follicle releases a mature egg at ovulation. But a polycystic ovary starts maturing at least twice as many follicles than normal, most of which enlarge and ripen but do not release an egg.

It is estimated that between 22 and 33 per cent of women have polycystic ovaries. Some women go on to develop polycystic ovary syndrome (PCOS), which means they have other symptoms in addition to polycystic ovaries.

PCOS happens when their hormonal system gets out of balance, making ovulation rare or irregular, and causing other changes in the body. Polycystic ovary syndrome is estimated to affect between 5 and 15 per cent of women of reproductive age, and it is thought to be more common in women of Asian descent.

What causes PCOS?
The real cause is still unknown to experts. However, research indicates that the root of the problem is most probably resistance to the hormone insulin, which means you need more insulin than usual to regulate the levels of sugar in the body. The extra insulin causes an imbalance in the hormones that usually make your menstrual cycle run smoothly.

Too much luteinising hormone (LH) is produced compared to follicle-stimulating hormone (FSH), which in turn causes the follicles on the ovaries to produce more of the male hormone testosterone than the female hormone oestrogen. The adrenal glands start to produce increased amounts of testosterone as well.

Too much testosterone prevents ovulation, along with other symptoms related to the syndrome. Oestrogen is still produced but, because the follicles never get to the point of maturity when progesterone production starts to increase, women with PCOS can be deficient in progesterone.

PCOS may be hereditary as well. Studies show that women with a family history of polycystic ovaries are 50 per cent more likely to develop PCOS.

How is it treated?
Your doctor will give you some lifestyle advice, about weight control and exercise, and will prescribe treatment based on how severe your symptoms are and whether you want to have children.

Women who do not want to get pregnant can use contraceptive pills or other drugs to correct hormone imbalances. Hormone treatments will regulate your menstrual cycle and may cut down on abnormal hair growth and acne.

Your doctor may also prescribe creams that help control excess facial hair, and creams or drugs to treat acne.

Drugs used in fertility treatment, such as clomifene, tamoxifen and gonadotrophins, can help women with PCOS who want to get pregnant.

If you are overweight, your doctor will advise lifestyle changes before trying fertility drugs. Even a modest weight loss can help your insulin levels get nearer to normal and get ovulation going again, if it has stopped. Losing weight before you conceive can also reduce your risk of developing gestational diabetes during your pregnancy.

Surgery can help some women to conceive if they have not responded to fertility drugs. The surgeon uses a technique called laparascopic ovarian drilling (LOD) to destroy the tissue on the ovaries that is producing testosterone.

The effects are often temporary, but LOD can improve the hormone imbalance and the ovulation cycle long enough for the woman to conceive. LOD is as effective as a treatment for infertility as the fertility drug gonadotrophin, with the advantage that it doesn't increase the risk of multiple pregnancy.

Insulin-sensitising drugs (ISDs), such as metformin, are now being used by specialists as treatments for polycystic ovary syndrome. Many PCOS women who didn't initially respond to a fertility drug responded to it after treatment with an insulin-promoting drug, but more evidence is needed that ISDs work before this treatment becomes widespread.

Metformin is also sometimes used by specialists as a treatment for infertility in women with PCOS, although the evidence that it really works is contradictory and it has some unpleasant side effects, such as nausea and vomiting.