Definition of polycystic ovary syndrome

This article aims to answer two questions in defining polycystic ovary syndrome (PCOS): what is PCOS and how should the syndrome be recognized in clinical practice? Whether PCOS is a primary or a secondary ovarian disease remains controversial. It has been suggested for many years that the main pathophysiological factor in PCOS is dysregulation of the relationship between the hypothalamus, the pituitary and the ovary. However, PCOS also involves intraovarian morphological and functional abnormalities. With respect to clinical practice, many reports have questioned the sensitivity as well as the specificity of a high LH concentration. Similarly, the biological hyperandrogenism of PCOS cannot define the syndrome. GnRH agonist or hCG tests are not convenient for the diagnosis of PCOS in practice. Stromal hyperplasia is considered to be indicative of PCOS but it is highly dependent on the settings of the ultrasound machine, thus use of the total ovarian area, the upper normal limit of which is 5.5 cm(2), is recommended. The need for diagnostic markers of PCOS depends on the clinical presentation. In the full-blown syndrome (classic PCOS), the clinical symptoms provide the most powerful indication and the association of the three components (hyperandrogenism, anovulatory dysfunction and metabolic abnormalities) has a strong diagnostic potency. In non-classic PCOS, a cost-effective and safe work-up should be applied, which includes ultrasonography and hormonal assays (basal serum concentrations of testosterone, sex hormone binding globulin, 17-hydroxyprogesterone, LH, FSH and prolactin). Asymptomatic PCOS may be discovered incidentally during ultrasonography, and it is important to take this finding into account when designing an ovulation induction protocol. In most cases of PCOS, the diagnosis may remain presumptive providing other diagnoses have been ruled out and the follow-up does not disclose any atypical development of the condition.