Introduction to Polycystic Ovary Syndrome (PCOS)
Polycystic ovary syndrome is the commonest hormonal disturbance to affect women. The main problems that women with PCOS experience are menstrual cycle disturbances (irregular or absent periods), infertility and skin problems (acne and unwanted hair growth on the face or body).
Not all women with PCOS experience all of the symptoms and furthermore a woman’s problems may change over time. In particular if an individual becomes overweight then her problems are likely to worsen. Many women with PCOS have difficulty in controlling body weight.
About 25-30% of women have polycystic ovaries, although a smaller proportion will have symptoms of the polycystic ovary syndrome – perhaps 15% of women. The problem therefore is extremely common, although many women have relatively mild symptoms.
Women have two ovaries which are situated in the pelvis alongside the uterus (womb). The ovaries have two main functions: the release of eggs and the production of hormones. The ovaries contain thousands of eggs which are present from birth. Each egg is surrounded by a group of cells which develop into a small fluid filled blister/cyst, called a follicle.
If a woman is having regular periods and is ovulating, one of these follicles grows to about 20mm diameter and then releases its egg, which then passes into one of the fallopian tubes. It is in the fallopian tube that fertilisation occurs and the fertilised egg (embryo) then travels into the uterus where it implants into the lining of the uterus (endometrium) and grows as a pregnancy. If fertilisation does not occur, the endometrium comes away as a menstrual period about 14 days after ovulation.
The second main function of the ovary is the production of hormones. Hormones are substances that are released into the blood stream and circulate around the body influencing other organs. The hormones from the ovary influence many parts of the body, in particular the uterus and breasts. There are many hormones that are released from the ovary and they fall into three main groups: oestrogens, androgens and progestogens.
Women make all of these hormones, but sometimes in different proportions. Testosterone is the main androgen hormone, made by the ovaries of all women. Oestrogen is made out of testosterone and helps the lining of the womb (endometrium) to grow.
Polycystic ovaries contain many small follicles which each contain an egg and have started to grow but do not reach a mature size. Instead, they remain at a size of about 2-9 mm in diameter. A polycystic ovary usually contains at least twelve of these small follicles or cysts. The ovaries are usually enlarged and their hormone producing tissue is also increased in size. The diagnosis is best made by an ultrasound scan which visualises the ovaries and the small cysts/follicles within them. Sometimes blood tests show characteristic changes in hormone levels, although these changes are not universal and can vary considerably between different women.
The small cysts in the ovaries do not get larger. Instead, they eventually disappear and are replaced by new cysts. They are not the type of ovarian cyst that require surgical removal and do not cause ovarian cancer.
The ultrasound picture is not always clear and some women with the syndrome may have an ultrasound scan that does not demonstrate it. However, the syndrome is defined by the presence of at least two out of the following three characteristics:
1) Signs or symptoms of high androgens (unwanted facial or bodily hair, loss of hair from the head, acne or an elevated blood level of testosterone) after other causes for this have been excluded
2) Irregular or absent menstrual periods after other causes for this have been excluded
3) Polycystic ovaries detected on ultrasound scan
Women with polycystic ovary syndrome may have the following hormonal disturbances:
Elevated levels of
• Testosterone: an ovarian androgen hormone that influences hair growth
• Oestrogen: an ovarian hormone that stimulates growth of the womb lining (endometrium)
• Luteinising hormone: a pituitary hormone which influences hormone production by the ovaries and is important for normal ovulation
• Insulin: a hormone that is principally involved in utilisation of energy from food, which when elevated may stimulate the ovary to over-produce testosterone and prevent the follicles from growing normally to release eggs and hence cause the ovary to become polycystic. Indeed, high levels of insulin are thought to be one of the main problems for women with polycystic ovary syndrome. Insulin becomes more elevated in women who are overweight.
There are many other subtle hormonal abnormalities that affect ovarian function and influence the menstrual cycle, fertility, bodily hair growth, body weight and general health.
What causes polycystic ovary syndrome?
It is now thought that having polycystic ovaries may run in families and there is evidence of a genetic cause. Some women may have polycystic ovaries and never have symptoms – or for that matter never know that they have polycystic ovaries. It appears that between 20 – 30% of women in the U.K. have polycystic ovaries, of whom perhaps three-quarters have symptoms. There are racial differences, with women from Southern Asia, for example, having a higher rate of PCOS and disturbed insulin metabolism than European Caucasian women.
Ovaries do not suddenly become polycystic, but women who have polycystic ovaries may develop symptoms at any time, for reasons that are not always clear. A gain in body weight is often the precipitating cause for the development of symptoms.
The appearance of polycystic ovaries does not disappear although symptoms may improve, either naturally or as a result of therapy.
It seems that one of the fundamental problems is with over production of insulin due to inefficient handling of energy from food. While the extra insulin is working hard, but ineffectively, to turn food into energy it fails and the food energy gets turned into high levels of sugars and fat.
The high levels of insulin have other effects in the body – including stimulating the ovaries to over produce androgens (mainly testosterone), preventing normal ovulation and also longer term effects on the circulation (leading to high cholesterol levels and an increased risk of cardiovascular disease: heart attack and stroke). There is also an increased risk of “late-onset” (Type 2) diabetes.
The balance of hormones is affected by body weight and being overweight can greatly upset this balance, worsening the above symptoms. Some women with polycystic ovaries only develop symptoms if they put on weight. Many clinics now measure sugar and cholesterol levels and if they are abnormal dietary advice is given. A high fibre, low fat and low sugar diet at a young age, together with regular exercise, may help to reduce problems such as high blood pressure and heart attacks when older. Smoking cigarettes seriously worsens the risk of developing these problems.
Another problem sometimes seen in later life is “late onset diabetes” where the body is unable to use sugar efficiently. If this occurs, it is necessary to reduce the dietary intake of carbohydrates and sometimes to take oral medication. The risk of both cardiovascular disease and diabetes can be reduced by keeping to the correct weight:height ratio.
1. Menstrual irregularities
Irregular and unpredictable periods can be unpleasant and a nuisance, as well as suggesting irregular ovulation and the risk of abnormal endometrial thickening. If pregnancy is not desired, the easiest approach is the use of a low dose combined oral contraceptive pill. This will result in an artificial cycle and regular shedding of the endometrium. Some women cannot take the pill and require alternative hormonal therapy to induce regular periods. We believe that it’s important to have a period at least once every three to four months to prevent abnormal thickening of the womb lining. An alternative is to use a progesterone secreting coil (Mirena Intrauterine System) which releases the hormone progesterone into the womb.
If ovulation occurs erratically it will take longer than average to get pregnant. When ovulation does not occur, it is not possible to conceive without treatment. If the menstrual cycle is irregular it is necessary to take steps to make it regular in order to achieve monthly ovulation and hence a better chance of conception. There are a number of treatments that are used to stimulate regular ovulation. Our clinic in Leeds is at the forefront of research in this area.
3. Skin problems
If androgen (testosterone) levels are high, the skin may be affected. Acne (spots) may occur on the face, chest or back. Sometimes, there is also unwanted hair growth on the face, chest, abdomen, arms and legs. These problems may be confined to small areas of the body, but sometimes they are more prominent, especially in women with darker hair or skin. A less common problem is thinning of hair on the head.
Being overweight probably causes the worst problems for women with the polycystic ovary syndrome, as obesity aggravates imbalances of the hormones that control ovulation and that affect the skin and hair growth.
Any contraceptive pill can be used to both regulate the menstrual cycle and improve acne and unwanted hair growth. Some pills contain specific “anti-androgens” such as cyproterone acetate (in Dianette) or drospirenone (in Yasmin). Spironolactone is another effective preparation, particularly for older women who may also have high blood pressure (for whom the contraceptive pill may not be allowable).
Physical treatments such as electrolysis and waxing may be helpful while waiting for the above medical treatments to work, as the drug therapies may take six to nine months or longer before any benefit is perceived. However electrolysis and waxing are expensive and should only be performed by properly trained therapists as scarring can result from unskilled treatment. Laser therapy has also proven effective, particularly for women with dark hair and fair skin. Shaving can help some women and does not make hair grow back faster.
There is a topical preparation eflornithine (Vaniqa) which appears to be very useful in reducing unwanted bodily hair. Vaniqa may cause some thinning of the skin and so high factor sun block is recommended.
Being overweight worsens the symptoms of PCOS. However, losing weight can be very challenging. PCOS does not lead to weight gain, but women with PCOS find it easy to gain weight as their metabolism may work inefficiently. Regular physical exercise (at least 30-60 minutes of hard exercise five to seven days per week) will increase the body’s metabolism and significantly improve the ability to lose weight as well as improving long term health.
Much has been written about diet and PCOS. The right diet for an individual is one that is practical, sustainable and compatible with lifestyle. It is sensible to keep carbohydrate content down and to avoid fatty foods. It is often helpful to sit down with a dietician to work out the best approach. A number of drugs are available that may help with weight loss. These can be prescribed by general practitioners and their use must be closely monitored. In some cases, bariatric surgery to either reduce the size of the stomach (gastric bypass) or place a band around the stomach (gastric banding) may be helpful.
To read more about PCOS, click here
For related research papers by Adam Balen, click here