Since the classical observation of Stein and Leventhal in 1935 (Stein and Leventhal 1935), interest in polycystic ovaries (PCO) and its associated syndrome (PCOS) has evolved from a “gynaecological curiosity to a multisystem endocrinopathy” (Homburg 1996). It is probably the most common endocrine disorder in women, accounting for the majority of cases of hirsutism, of menstrual disturbance, and anovulatory infertility. It is also one of the most poorly defined endocrinological conditions with a complex pathophysiology that has produced considerable scientific debate. Evidence of the ongoing interest in this disorder is not difficult to find; an electronic search on medline from 1966 to 2005 using the search term “polycystic ovary syndrome” produces 5112 citations; 934 are review articles, and 200 are randomized controlled trials (Fig. 2.1), and the majority of publications occur after 1985.

Recognition

Although Stein and Leventhal were first in the modern medicine era to describe this condition, an earlier description dating back to 1721 reads: “Young married peasant women, moderately obese and infertile, with two larger than normal ovaries, bumpy, shiny and whitish, just like pigeon eggs.” (Vallisneri 1721; translated from Italian.) There was further recognition in the nineteenth century when sclerocystic changes in the ovary were described (Chereau 1844), but it was not until Stein and Leventhal first presented their paper at the Central Association of Obstetricians and Gynecologists in 1935 that the syndrome was more comprehensively described.