The Basics of Polycystic Ovarian Syndrome

Polycystic ovarian syndrome (PCOS) is the most common endocrine disturbance in women of reproductive age; it affects an estimated 5 to 10 percent of females. PCOS, also called Stein-Leventhal Syndrome after the doctors who first characterized it in the 1930s, is a cause of infertility. It is also now associated with long-term risks of diabetes and cardiovascular disease.

As the term polycystic ovarian syndrome suggests, PCOS often is accompanied by enlarged ovaries containing multiple small cysts. During the normal ovulatory process, an egg is stimulated in an ovarian follicle, which then ruptures and releases the egg. In women with PCOS, high levels of hormones called androgens halt the normal hormonal process and the egg’s development. These follicles — whose appearance (via an ultrasound) is sometimes likened to a string of pearls — form the cysts observed in PCOS.


Note that the name is a bit misleading — not every woman with PCOS has cysts, and many women who have cysts don’t have PCOS.

While the biochemical imbalances that cause symptoms are becoming better understood, the trigger for PCOS is unknown. Researchers suspect that genetic predisposition plays a role. One recent study at Mount Sinai Hospital in New York found a possible connection between a gene that helps the body use insulin and PCOS. Other studies have found that excess insulin production stimulates testosterone production and leads to insulin resistance, which is a precursor to type II diabetes. Other studies have noted excess insulin production in the presence of insulin resistance.

The most visible symptoms of PCOS stem from excessive levels of androgens, such as testosterone, which in women are produced in the ovaries, adrenal glands and fat cells. Testosterone can be converted to a more powerful androgen, dihydrotestosterone (DHT), in areas that affect the skin and hair. Even though androgens are found in both men and women, they are usually present at much higher concentrations in men and are an important factor in male traits and reproductive activity. Androgens include testosterone, DHT and androstenedione. Other hormones can be converted into testosterone or DHT, including dehydroepiandrosterone (DHEA), DHEA sulfate and estradiol, which are also considered androgens.

Copyright 2003 National Women's Health Resource Center Inc. (NWHRC)


The Basics of Polycystic Ovarian Syndrome (<i>cont'd</i>)

Excessive levels of these hormones (hyperandrogenism) in women can lead to some of the most common symptoms of PCOS, including:

  • excess body or facial hair
  • oily skin and acne
  • oligo ovulation
  • weight gain

But such symptoms alone are not enough to support a diagnosis of PCOS. They may only indicate hyperandrogenism, which can result from several conditions and can be treated with anti-androgen medications.


The diagnosis of PCOS hinges on irregular and/or infrequent ovulation, as indicated by irregular menstrual periods. If periods are absent, it is important to induce them from time to time, whether through daily birth control or less frequent courses of the hormone progesterone. Menstruation prompts the shedding of the uterine lining, which protects against endometrial cancer.

PCOS often is a cause of infertility due to failure to ovulate. The usual course of treatment here is a drug called clomiphene citrate. If that doesn’t work, the next step is injectable gonadotropins. Many health care professionals are increasingly prescribing insulin-sensitizing drugs designed to treat diabetes to induce ovulation with or without clomiphene citrate. Small studies indicate such drugs alone or in combination with ovulatory medication may be effective for both infertility and other symptoms of PCOS.

PCOS is strongly linked to obesity and insulin resistance (a precursor to type II diabetes). About one-third of women with PCOS who are obese have insulin resistance or type II diabetes. For women with PCOS who are obese, a treatment plan will usually incorporate a diet and exercise program.

Obesity in women with PCOS tends to be centered on the abdomen, a fat distribution pattern linked to increased risk of diabetes, heart disease and high blood pressure. Due most likely to underlying endocrinological dysfunction, women with PCOS are more apt to gain weight and have more trouble losing weight.

There is no cure for PCOS. Health care professionals usually address the symptoms that are most bothersome to a particular woman. Because of the complexity of the hormonal interactions, you may need to see an endocrinologist or a reproductive endocrinologist (especially if you are infertile and trying to conceive).

For many, the syndrome begins at puberty, with irregular or absent periods, but for others PCOS symptoms first become noticeable in their early 20s. Onset of PCOS becomes less likely as a woman ages. The metabolic endocrine abnormalities of PCOS are possible even for women whose ovaries have been removed, because androgens can be produced elsewhere in the body.

Copyright 2003 National Women's Health Resource Center Inc. (NWHRC)