What are polycystic ovaries?

Polycystic ovaries are characterised by the presence of many small cysts (fluid filled swellings) around the surface of the ovaries. The cysts are quite small ranging from 2 to 8 mm (Figure 7.1).

Polycystic ovaries are usually larger than normal ovaries and their central substance is generally more dense.

Over recent years, with the advent of ultrasound examination, we have learned that about one woman in five has polycystic ovaries. At ultrasound examination, the ovaries appear larger and more dense and the cysts look like a "necklace" around the periphery of the ovaries.

Figure 7.1 Polycystic Ovary Picture - Note The Small Cysts Around The Periphery Of The Ovaries

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What is polycystic ovary syndrome?

When patients develop symptoms associated with their polycystic ovaries, they are said to have polycystic ovary syndrome ( or polyscystic ovarian syndrome).

Of the 20% of women who have PCO only one in three will have symptoms - PCOS.

In addition to abnormal menstrual cycles and infertility, some women may be troubled by skin problems, notably acne and greasy skin or unwanted hair production (hirsutism).

PCOS was first described by Stein and Leventhal in 1935 and the condition is therefore also known as Stein-Leventhal syndrome.

Many women with PCOS find it difficult to understand why they have developed symptoms, such as irregular and infrequent periods (oligomenorrhoea), after many years of normal cycles. Usually, the key factor to account for the change is an increase in weight. In association with PCOS there may be an increased level of insulin which encourages the body to lay down excessive amounts of fat tissue leading to obesity. This excess fat tissue aggravates the hormonal imbalance. A spiral may be set up as the hormone problems increase fat production and the excess fat has a further adverse effect on the hormone balance.  

Part of the difficulty in understanding polycystic ovary syndrome (PCOS) and interpreting the large medical literature surrounding it has been that there was no universally accepted clinical definition.⁽⁰³⁰¹⁾

There has been a recent consensus on the diagnosis of polycystic ovary syndrome^.(0401)

PCOS is defined as the presence of any two of the following three criteria:

PCOS Causes

Although a great deal is now known about the polycystic ovary syndrome, the exact cause has yet to be determined.

Polycystic ovary syndrome is probably an inherited condition. There has been one specific gene implicated and two others also seem to be involved. Premature balding in men is often a manifestation of the same gene that results in PCOS in women.

The hormone chemistry of polycystic ovaries is often deranged. This may result in period problems, particularly reduced or absent periods. Polycystic ovaries tend not to release their eggs regularly and, without treatment, there may be problems with fertility.

In recent years it has become recognised that many of the metabolic (body chemical) changes seen in PCOS may be related to insulin resistance.^{0301, 9901}

Insulin is produced by the pancreas, which is a gland found in the abdomen. This gland has two functions, both related to the way the body deals with food. It secretes enzymes (chemical catalysts) into the small bowel allowing food to be broken down into the basic components that can be absorbed. The pancreas also secretes insulin into the blood stream. Insulin is a hormone  that reduces the blood sugar level, mainly by converting sugar into fat. Diabetes occurs when the pancreas can no longer produced sufficient insulin to prevent the blood sugar level rising too high. It turns out that most women with PCOS are resistant to insulin. Hormones work like a key in a lock. Insulin resistance means that the insulin hormone receptors are defective and a stronger key is required. The result is an increased output of insulin and it is the higher levels of insulin that seems to result in the typical symptoms of PCOS. Women with PCOS are not diabetic and so there is no difference in their response to a glucose (sugar) load (Figure 7.2).

Figure 7.2 Glucose Tolerance Test - Normal and PCOS women

Typically, women with PCOS require greater output of insulin from the pancreas to prevent their sugar rising too high (Figure 7.3).

 

Figure 7.3 Insulin Response to Glucose Load - Normal and PCOS

 

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It is becoming recognised that some patients have symptoms and blood chemistry (hormone levels) typical of polycystic ovary syndrome, although their ovaries do not have a typical PCO picture. The latest definition of PCOS allows for this.⁰⁴⁰¹

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How prevalent is polycystic ovary syndrome?

Polycystic ovary syndrome is one of the most common endocrine (hormone) disorders. Ultrasound examination provides an excellent window to look at ovarian structure. The ovaries are close to the top of the vagina and therefore transvaginal scanning shows of ovarian structure more clearly than transabdominal scanning.

In adult women, transvaginal scanning reveals an incidence of PCO in the order of 20%. About one in three with ultrasound evidence of PCO will have problems resulting in an incidence of 6-10%.

Before sexual activity has commenced ultrasound is performed by the transabdominal route. Evidence of PCO can be found in 6% of six year old girls and, by the age of ten, 18% of girls have evidence of PCO.

There is evidence that PCOS is more prevalent amongst those that are obese and in those with Type 1 diabetes or who have had gestational diabetes.

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For how long will I have polycystic ovary syndrome?

Unfortunately, PCOS is a problem that does not disappear. It is almost certainly an inherited condition. Just like the colour of your eyes, it cannot be changed.

Will polycystic ovary syndrome affect my general health?

There is a spectrum of severity of PCOS ranging from a little irregularity of the menstrual cycle to troublesome excess body hair and anovulatory infertility.

Early suggestions that PCOS is a cause of heart disease seems to have been unfounded. Obesity, however, is associated with heart problems and many women with PCOS are overweight. There is evidence that the long-term complications of PCOS are increased by the addition of obesity.

Young, obese women with PCOS have a high prevalence of early asymptomatic coronary atherosclerosis, compared with obese controls. This increased risk is independent of traditional cardiovascular (CV) risk factors and novel markers of inflammation. These findings underscore the need to screen and aggressively counsel and treat these women to prevent symptomatic CV disease.⁰⁷⁰¹

If you have PCOS, you should make every effort to keep your weight down by diet and excercise.

Between 20 and 40% of women found to have polycystic ovary syndrome will develop diabetes in later life. As PCOS is associated with anovulation, the endometrium may be subjected to long-term oestrogen without cyclical progesterone protection increasing the risk of endometrial cancer (endometrial cancer).

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What hormone changes are typical of polycystic ovary syndrome?

Blood tests to evaluate PCOS should be scheduled early in the menstrual cycle. Some prefer the third day of the cycle and others the eighth day.

Elevated LH (menstrual cycles) concentrations, seems to be the most common finding.

The androgenic hormones (steroid hormones) testosterone and androstenedione tend to be increased and these higher levels tend to be associated with decreased SHBG levels (SHBG).

Prolactin levels (menstrual cycles, hyperprolactinaemia) are often just above the normal range. As hormone levels fluctuate there may be merit in repeating the tests.  After food insulin levels rise higher than normal (PCOS cause;  Figure 7.3).