Polycystic ovary syndrome: Where we stand with diagnosis and treatment and where we’re going

• waist circumference, more than 35 inches
• triglycerides level, at least 50 mg/dL
• high-density lipoprotein-C level, greater than 50 mg/dL
• systolic BP, 130 mm Hg or higher, and diastolic BP, 85 mm Hg or higher
• fasting glucose level (after an oral glucose tolerance test) between 110 and 126 mg/dL or a 2-hour postprandial glucose level between 140 and 199 mg/dL, or both.

Prevalence

Data are scarce, making the prevalence of PCOS difficult to estimate—in part, because PCOS is a heterogeneous condition that can manifest with variable clinical evidence:

• hyperandrogenism—as either hirsutism, acne, or alopecia, or a combination of these signs
• menstrual or ovulatory dysfunction, or both
• overweight or obesity
• infertility
• insulin resistance and other metabolic abnormalities
• polycystic ovaries

Now that accepted diagnostic criteria for PCOS are in place, the prevalence rate of the syndrome will be easier to establish. In the discussion that follows, we attempt to establish estimates of prevalence based on histopathology, signs of clinical hyperandrogenism, and the US appearance of polycystic ovaries.

When PCOS is defined histopathologically (i.e., by the presence of polycystic ovaries at the time of oophorectomy or wedge resection), 1.4% to 3.5% of unselected women⁶ and 0.6% to 4.3% of infertile women⁷ have this syndrome.

When clinical criteria are used, prevalence varies with the clinical complaint. Hirsutism is usually a mark of increased ovarian or adrenal androgen production. Studies—including one in which more than 1,000 women were evaluated using the 1990 National Institutes of Health (NIH) criteria (see the next section)—suggest that, in fact, more than 75% of hirsute women have PCOS.^8,9

In the absence of frank hirsutism, when only unwanted facial hair is present, approximately 50% of these women meet the definition for having PCOS.¹⁰

Among women whose only complaint is acne, prevalence has been reported in as many as one-third (range, 19% to 37%, although diagnostic criteria for PCOS were not well defined in these three studies).^11-13

Last, in women who had any manifestation of clinical hyperandrogenism by the 2003 Rotterdam criteria (hirsutism, acne, or alopecia, or a combination; again, see the next section), PCOS was diagnosed in 72%.¹⁴

When PCOS is defined by a finding of polycystic ovaries on US, prevalence varies by study settings. Polycystic ovaries are seen in 92% of women who have idiopathic hirsutism¹⁵; in 87% of women who have oligomenorrhea¹⁵; in 21% to 23% of randomly selected women^14,16; and in 23% of women who described themselves as “normal” and reported having a “regular” menstrual cycle.¹⁷ However, up to 25% of women with polycystic appearing ovaries may be entirely asymptomatic.¹⁸

In contrast, not all women who have an excess of androgens have polycystic-appearing ovaries^19-21; this situation has been observed in 20% to 30% of young, healthy women.⁹

When biochemical parameters are used as diagnostic criteria, the prevalence of PCOS varies from 2.5% to 7.5%.²² In an unselected, minimally-biased population of women, overall prevalence of PCOS appears to be approximately 4.6%, although it could be as low as 3.5% and as high as 11.2%.²³

All these observations, findings, and criteria considered, it is generally accepted that PCOS is one of the most common reproductive endocrine disorders of women.

What are the diagnostic criteria for PCOS?

Since the original description in 1945 of the diagnostic criteria of PCOS—irregular menstruation, infertility, obesity, hirsutism—it’s become clear that this disorder is a heterogeneous condition. Some patients display classic symptoms; many have a mild variant.

NIH seeks clarity. To further understand and study PCOS, it was essential to standardize the definition to facilitate collaborative clinical trials. In 1990, an NIH-sponsored consensus workshop attempted to standardize the criteria for making a diagnosis of PCOS.²⁴ This included a combination of:

• chronic anovulation
• clinical (hirsutism) or biochemical (or both) signs of hyperandrogenism
• exclusion of other causes (including thyroid dysfunction, hyperprolactinemia, and adult-onset congenital adrenal hyperplasia).

A diagnosis of PCOS did not, however, require that the ovaries have polycystic characteristics on US imaging. In contrast, the European definition of PCOS was a syndrome that included polycystic ovaries on US in conjunction with clinical or biochemical hyperandrogenism; oligomenorrhea or amenorrhea; and obesity.

International consensus sought. To foster agreement across borders, a joint workshop of the European Society of Human Reproduction and Embryology and the American Society for Reproductive Endocrinology workshop was held in Rotterdam in 2003,^25,26 resulting in an updated definition of PCOS. Ovarian morphology of multifollicular-appearing ovaries on US was recognized as an important component of the diagnosis; women who had clinical or biochemical hyperandrogenism in the face of a normal menstrual cycle could, therefore, have PCOS.