Polycystic Ovarian Syndrome (PCOS)

What is PCOS?

Polycystic ovarian syndrome affects approximately about 4% of all reproductive-aged women.  PCOS is the most common hormone disorder in reproductive-aged women and is a leading cause of female infertility. PCOS is characterized by amenorrhea (no menses), hirsutism (i.e., excessive body hair growth), and the presence of polycystic ovaries.

Polycystic ovaries (an elevated number of a small antral follicles, small ovarian cysts 2-6 mm in diameter) are a distinguishing characteristic.  Polycystic ovaries are a common finding in patients with PCOS, but do not solely define the condition. 

In addition to polycystic ovaries, PCOS is a clinical diagnosis based on irregular ovulation and signs of excessive androgen (male-type hormones).  Irregular menses is a hallmark for an individual who does not ovulate regularly. Since the lack of ovulation is a central feature of the syndrome, many patients will suffer from infertility. Due to the heterogeneity of the syndrome, guidelines have been established to confirm the diagnosis. Typically, the diagnosis is established by excluding other causes of irregular ovulation, followed by confirmation of the presence of symptoms and/or lab finings consistent with PCOS.

Table 1 lists the most frequent features of the condition.

Symptoms of PCOS

What causes PCOS?

The syndrome is a result of a functional hormonal disorder that disrupts normal ovarian function. It is best thought of as an imbalance of hormones that control the ovary’s ability to mature and release an egg. Normally, the pituitary gland (which sits at the base of the brain) produces hormones (gonadotropins) that drive the selection, growth, and ultimately ovulation from ovarian follicles (the structures that contain eggs).  In women with PCOS, the follicles exhibit a resistance to physiologic gonadotropin levels.

The reason why the ovary fails to respond to the gonadotropins in women with PCOS is not well understood. It is believed that there are elevated “resistance factors” that inhibit the ovaries ability to function normally. Some of these resistance factors are androgens and insulin-like growth factors. 

How is PCOS treated?

The most important concept in treating PCOS is first determining what you desire to treat. Generally, the therapeutic options are directed at one or more of the following: 1) Restoring normal menstrual cycles 2) Reducing symptoms of excess hair growth or oily skin 3) and restoring normal fertility.

Oral contraceptive pills (OCPs) are the most effective method to restore normal cycles and reduce symptoms of excess hair growth. Besides OCPs, a common anti-androgen is spironolactone, which can be added to a OCP regimen. Others anti-androgen treatments include finasteride, flutamide and cyproterone acetate. Since hair growth and turnover occur over a long time, the results of decreasing hirsutism with these agents sometimes takes 3–6 months to appreciate an effect.

Restoring fertility involves increasing pituitary gonadotropin secretion until levels overcome the natural resistance of the PCOS follicle. There several types of fertility medications that can be used to accomplish this.  Letrozole and Clomiphene citrate are the most commonly used first line medications. They are oral medications that work by stimulating the pituitary to increase FSH secretion. In cases that have failed oral therapy, subcutaneous gonadotropins injections can be used to try to overcome the resistance of PCOS follicle. 

Virtually every patient with PCOS can be treated effectively. Because the symptoms are so diverse, no single treatment fits all conditions. It is essential to recognize the syndrome, determine the desired treatment goals and develop an appropriate treatment plan to achieve those goals.