The Polycystic Ovary Morphology-Polycystic Ovary Syndrome Spectrum

Abstract Background Polycystic ovary syndrome (PCOS) is the most common cause of chronic hyperandrogenic anovulation. Two-thirds of PCOS patients have functionally typical PCOS, with typical functional ovarian hyperandrogenism manifest as 17-hydroxyprogesterone hyper-responsiveness to gonadotropin stimulation. Most, but not all, of the remainder have atypical functional ovarian hyperandrogenism. Many asymptomatic volunteers with polycystic ovary morphology (PCOM) have similar abnormalities. Objective The objective of this paper is to review the relationship of biochemical ovarian function to the clinical spectrum observed in PCOS and in normal volunteers with PCOM. Findings Adolescents and adults with PCOS are similar clinically and biochemically. Ninety-five percent of functionally typical PCOS have classic PCOS, ie, hyperandrogenic anovulation with PCOM. In addition to having more severe hyperandrogenism and a greater prevalence of PCOM than other PCOS, they have a significantly greater prevalence of glucose intolerance although insulin resistance is similarly reduced. Half of normal-variant PCOM have PCOS-related steroidogenic dysfunction, which suggests a PCOS carrier state. Conclusions There is a spectrum of ovarian androgenic dysfunction that ranges from subclinical hyperandrogenemia in some normal-variant PCOM to severe ovarian hyperandrogenism in most classic PCOS. A minority of mild PCOS cases do not fall on this spectrum of ovarian androgenic dysfunction, but rather seem to have obesity as the basis of their hyperandrogenism, or, less often, isolated adrenal androgenic dysfunction. Half of normal-variant PCOM also do not fall on the PCOS spectrum, and some of these seem to have excessive folliculogenesis as a variant that may confer mild prolongation of the reproductive lifespan. Improved understanding of PCOM in young women is needed.