Received December 11, 2005; Accepted December 11, 2005. Author to whom all correspondence and reprint requests should be addressed: F. J. Broekmans, MD, PhD, Department of Reproductive Medicine, Uni- versity Medical Center, Heidelberglaan 100, 3584 CX Utrecht, The Nether- lands. E-mail: f.broekmans@azu.nl Diagnostic Criteria for Polycystic Ovarian Syndrome F. J. Broekmans and B. C. J. M. Fauser Department of Reproductive Medicine and Gynecology, University Medical Center, Utrecht, Heidelberglaan 100, 3584 CX Utrecht Endocrine, vol. 30, no. 1, 3–11, August 2006 0969–711X/06/30:3–11/$30.00 ENDO (Online) ISSN 1559-0100 © 2006 by Humana Press Inc. All rights of any nature whatsoever reserved. 3 lengthy debates among clinicians (6,7). Specialty groups may still differ in their use of diagnostic criteria and diag- nostic work up, as well in their choice of first- and second- line treatment (7). At the expert consensus meeting held in 2003 in Rotter- dam (3,8), it was agreed that the polycystic ovary syn- drome should be diagnosed in cases of WHO II anovulation if at least two of the following three features were present: (1) oligomenorrhea or amenorrhea, (2) clinical or biochem- ical hyperandrogenism, and (3) polycystic ovaries at ultra- sound. The approach of only requiring a certain number of relevant features to diagnose a disease state or clinical con- dition is not without precedent. For instance, for the diag- nosis of the metabolic syndrome it was decided that only three out of five key criteria should be present (9,10). Several commentaries have since emerged continuing the debate on the definition and classification issue and have suggested adaptations in the set of diagnostic criteria (11–13). The Rotterdam consensus, however, is indeed a compromise, which bridges the immense gap between the European and American perspectives with regard to PCOS. It is anticipated that with the use of consensual diagnostic criteria among physicians working in the field of both endocrinology and gynecology the comparability of published research will increase and the search for etiological factors will lead to improved results of patient management. It is therefore recommended that all clinicians and investigators now use this internationally agreed definition to ensure uniformity in research studies and routine clinical management. In this section much of the background for the use of the so-called Rotterdam criteria will be discussed. Also, asso- ciated features will be addressed, such as obesity, elevated serum LH, insulin resistance, and the metabolic syndrome. Those features are frequently present in PCO patients with- out contributing to the diagnosis per se, and may well have consequences for long-term health and as such should be recognized. Also, risks for cancer development based on unopposed estrogen exposure are briefly discussed. Finally, the necessity for the exclusion of other explaining causes for the phenotypic features will be addressed and a diagnos- tic work up scheme presented. In the original description of the syndrome, the histolog- ical confirmed polycystic nature of ovarian architecture was the primary abnormality. The association between endocrine Until recently no universally accepted clinical defini- tion existed for the polycystic ovary syndrome (PCOS). What has emerged from research over the last 30 yr is a profound heterogeneity and ongoing speculation regarding etiology. The various symptoms and signs related to PCOS have now been extensively evaluated as to their possible contribution to the diagnosis. Con- sensus has been reached for the use of oligomenorrhea or amenorrhea, clinical or biochemical hyperandrog- enism, and polycystic ovaries at ultrasound as key diag- nostic criteria. Obesity, insulin resistance, and the so-called metabolic syndrome should be recognized as associated conditions that present long-term health risks for diagnosed PCOS cases. The way all these fea- tures need to be applied in the work up of the indi- vidual index patient is reviewed here. Key Words: Polycystic ovary syndrome; consensus; ultrasonography; hyperandrogenism; anovulation. Introduction The history of the diagnostic challenge of a condition currently referred to as the polycystic ovary syndrome (PCOS) goes back some 70 yr. It was in 1935 that Stein and Leventhal described several cases presenting with oligo- menorrhea/amenorrhea combined with the presence at operation of bilateral polycystic ovaries (PCO) (1). Of these seven patients, three also presented with obesity and five showed signs of hirsutism. Only one patient was both obese and showed hirsutism. These findings indicate that in cases with polycystic ovaries proven by morphology not all of the features associated with the PCOS necessarily have to be present (2,3). With the introduction of transvaginal ultra- sonography it also became clear that patients with oligo- menorrhea, obesity, and hirsutism do not necessarily have the typical polycystic morphology on ultrasound (4,5). More- over, as the etiology of PCOS is far from well understood, diagnostic criteria for PCO syndrome have been subject of