Diagnostic criteria in polycystic ovary syndrome.

Part of the difficulty in understanding polycystic ovary syndrome (PCOS) and interpreting the dense literature surrounding it is that there is no universally accepted clinical definition. The varying definitions influence the incidence, prevalence of sequelae, and response to treatment. PCOS is clearly heterogeneous and its etiology is still speculative. Over the years it has evolved from a "disease" to a "syndrome," the latter which includes a variety of potential signs and symptoms, including oligo-ovulation, biochemical or clinical hyperandrogenism, polycystic ovaries, and insulin resistance. There is no single diagnostic criterion that can be recommended for diagnosis of PCOS. While hyperandrogenemia, specifically elevated bioavailable testosterone, is intellectually appealing, the evidence in terms of long-term sequelae identified by such a test is still weak. The recognition of oligo-ovulation primarily relies on patient history. Currently both consensus and the preliminary evidence-based trials support a combination of hyperandrogenemia and oligo-ovulation, in the absence of known causes, as diagnostic criteria, but there are also strong proponents of using ovarian morphology to identify and diagnose the syndrome. There are no simple clinically validated biochemical tests of insulin resistance. Further identification of specific causes, and elimination of the multiple phenocopies that make up PCOS, will ease its diagnosis.