Polycystic Ovaries and Normal Women Their Structure and relationship to PCOS

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). The 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 Ovaries - Note The Small Cysts Around The Periphery Of The Ovaries

Related Medical Abstracts - Click on the paper title:-

• A common finding in normal women. (1988)
• A new ultrasonic classification. (1995)
• Interrelationship between ultrasonography and biology in the diagnosis of polycystic ovarian syndrome. (1993)

There has been a recent consensus on the diagnosis of polycystic ovary syndrome^.(0401) and the presence of polycystic ovaries on ultrasound is a significant factor.

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

1. polycystic ovaries (either 12 or more follicles measuring 2-9 mm in diameter, or increased ovarian volume (> 10 cm³) on ultrasound.
2. oligomenorrheoa / anovulation  (reduced periods / failure to release eggs).
3. clinical or biochemical evidence of hyperandrogenism (excessive male hormone).

Some women with PCOS do not have polycystic ovaries (PCO), nor do all women with ovarian cysts have PCOS.

Although a pelvic ultrasound is a major diagnostic tool, it is not the only one. The diagnosis is confirmed using the Rotterdam criteria, even though the syndrome is associated with a wide range of symptoms.

Diagnostic assessments for PCO to be PCOS:

• History-taking, specifically for menstrual pattern, excessive body weight, hirsutism (excess body hair), and the absence of breast discharge (galactorrhoea).
• Pelvic ultrasonography, specifically looking for small ovarian follicles. These are the result of disturbed ovarian function with failed ovulation, reflected by the infrequent or absent menstrual cycles that is typical of the condition. In normal menstrual cycle, one egg is released from a dominant follicle - essentially the ovarian follicle (cyst) that bursts to release the egg. In PCOS, there is  "follicular arrest" - several follicles develop to a size of 5-7 mm, but no further. No single follicle reaches the preovulatory size (16 mm or more). According to the Rotterdam criteria, 12 or more small follicles should be seen in an ovary on ultrasound examination. The follicles may be oriented in the periphery, giving the appearance of a 'string of pearls'. The numerous follicles contribute to the increased size of the ovaries, that is, 1.5 to 3 times larger than normal.
• Laparoscopic examination may reveal a thickened, smooth, pearl-white outer surface of the ovary. This is often an incidental finding if laparoscopy were performed for some other reason, as it would not be routine to examine the ovaries in this way to confirm a diagnosis of PCOS.

See Also:

PCOS - Polycystic Ovary Syndrome

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This is the personal website of David A Viniker MD FRCOG, retired Consultant Obstetrician and Gynaecologist - Specialist Interests - Reproductive Medicine including Infertility, PCOS, PMS, Menopause and HRT.
I do hope that you find the answers to your women's health questions in the patient information and medical advice provided.

- Specialist Interests - Reproductive Medicine including Infertility, PCOS, PMS, Menopause and HRT.

I do hope that you find the answers to your women's health questions in the patient information and medical advice provided.

The aim of this web site is to provide a general guide and it is not intended as a substitute for a consultation with an appropriate specialist in respect of individual care and treatment.