The basics - Polycystic ovary syndrome

Dr Louise Newson explains how to diagnose and treat this common condition.

Polycystic ovary syndrome (PCOS, formerly known as Stein-Leventhal syndrome) is the most common hormonal disturbance in women. PCOS is characterised by anovulation and hyperandrogenism, with clinical manifestations of irregular menstrual cycles, hirsutism, alopecia, acne and infertility. It is very common; around one fifth of women in the UK are affected. It is also the most common reason for women not to ovulate leading to infertility.

Diagnosis of PCOS
The diagnosis can only be made when other conditions have been excluded (thyroid dysfunction, congenital adrenal hyperplasia, hyperprolactinaemia, androgen-secreting tumours and Cushing's syndrome).

The definition of PCOS has recently been replaced by the Rotterdam European Society for Human Reproduction and Embryology and the American Society of Reproductive Medicine PCOS Consensus Workshop Group. This has suggested a broader definition for PCOS, with two of the three following criteria being diagnostic:

  •  Polycystic ovaries on ultrasound scan.
  • Oligo- or anovulation.
  • Clinical and/or biochemical signs of hyperandrogenism.

A raised luteinising hormone (LH): follicle-stimulating hormone ratio is no longer a diagnostic criterion for PCOS.

Only 40 per cent of women with confirmed PCOS are overweight, although symptoms are generally worse as weight increases indicating that this is likely to be a key trigger in the disease process.

Complications of PCOS include obesity, hypertension, hypertriglyceridaemia and type-2 diabetes. The key underlying abnormality that leads to long-term health risk appears to be insulin resistance (hyperinsulinaemia in the presence of normoglycaemia).

Obese patients with PCOS should have their fasting glucose tested. Insulin resistance in PCOS has been linked to a later development of impaired glucose tolerance and also type-2 diabetes.

Risk factors
By the age of 40, up to 40 per cent of patients will have type-2 diabetes or impaired glucose tolerance.

Patients at highest risk are those with central obesity and also those with a family history of diabetes. These patients should have their cardiovascular risk assessed and managed appropriately.

Oligo- and amenorrhoeic women with PCOS may develop endometrial hyperplasia and later carcinoma. It is recommended that treatment with progestogens to induce a withdrawal bleed at least every three to four months should be given. One regimen would be 5mg of norethisterone three times per day for 10 days.

PCOS patients, in particular those with raised LH levels, are at increased risk of miscarriage. It is estimated that 30-50 per cent of pregnancies in women with PCOS end in miscarriage.

Interestingly, sleep apnoea is more common in patients with PCOS, even adjusting for BMI. As sleep apnoea is an independent cardiovascular risk factor it is important that sleep apnoea is diagnosed and managed appropriately.

An MRI scan showing multiple cysts on the ovaries of a woman with polycystic ovary syndrome

Management
The management of patients with PCOS differs according to the individual symptoms and concerns.

For example, management of infertility may be an issue for some patients whereas suitable contraception and regular menstruation may be more appropriate for others.

Weight reduction and maintenance of normal BMI is very important in obese patients with PCOS. They should be on a low-fat and low-sugar diet.

Weight loss has been shown to improve infertility by improving cycle control and the likelihood of ovulation. Cosmetic treatments and eflornithine can be very useful for hirsutism.

Oral contraception
The combined contraceptive Pill is a good choice of treatment as taking it leads to regular menstruation.

Estrogen stimulates hepatic sex hormone-binding globulin production, resulting in lower serum levels of free androgens.

It also directly suppresses LH secretion, and hence LH-mediated androgen secretion by the ovary.

Preparations including the anti-androgen cyproterone may be beneficial.

Co-cyprindiol can also improve hirsutism.

There is no convincing evidence that the combined oral contraceptive Pill is likely to contribute to diabetic risk in women with PCOS.

Androgen suppression with oral contraceptives is, however, associated with a significant elevation in triglycerides as well as HDL levels so may be inadvisable in patients with established hypertriglyceridaemia.

As yet there is no evidence to suggest that women with PCOS experience more cardiovascular events than the general population when taking oral contraceptives.

Metformin
Metformin is an oral hypoglycaemic agent that has been shown to reduce serum concentrations of insulin and androgens, reduce hirsutism, and improve ovulation rates.

Metformin is often used for patients with PCOS to reduce insulin resistance and reduce the risk of developing diabetes.

However, results from a diabetes prevention trial that examined a cohort of patients who had similar metabolic profiles to women with PCOS found that metformin is not actually superior to lifestyle intervention in improving both cardiovascular risk and progression to type-2 diabetes.

Metformin is still unlicensed for use in patients with PCOS.

Anovulation associated with PCOS is sometimes treated by laparoscopic ovarian electrocautery. This can result in regular ovulation and reduction of serum androgens in over 60 per cent of patients.

  • Dr Newson is a GP in the West Midlands

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