Smita is distraught. Her 17 year old daughter has irregular periods. Her family physician ordered an ultrasound and she has been diagnosed as having polycystic ovary syndrome. Her mind is whirling with questions. Will her daughter need surgery? Can she ever have children?

Polycystic ovary syndrome (PCOS) is the most common endocrine disturbance in women of reproductive age. It affects an estimated five percent to 10 percent of females. PCOS is a common cause of irregular periods and infertility. Like the other metabolic disease diabetes, there is a sharp increase in the incidence of PCOS in Indian women.

What does polycystic ovary mean?

During a normal menstrual cycle, a small number of follicles begin to grow. One becomes the biggest, outgrowing the rest. This dominant follicle 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 immature or underdeveloped follicles are what are called "cysts" in PCOS.

A "polycystic" ovary generally is defined as having more than 10 follicles, and the ovary by itself may be larger than normal.

Note that the name is a bit misleading. Up to 30 percent of women with PCOS do not have polycystic-looking ovaries and many women who have polycystic ovaries do not have PCOS.

Why does PCOS occur?

Researchers suspect that a genetic predisposition plays a role. The biochemical imbalances that cause symptoms are becoming better understood. One of the trigger points maybe excess insulin production, which can result from insulin resistance. This stimulates testosterone production (a type of male hormone or "androgen").  Insulin resistance is also a precursor to Type II diabetes (diabetes which may not require insulin for treatment).