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)