Diagnostic criteria for PCOS: Is there a need for a rethink?

The diagnostic criteria for polycystic ovarian syndrome (PCOS) have been grouped in different classifications that have been conflicting for many years. At present, the classification of Rotterdam is the most used, but with varying frequency depending on the country and medical specialties. This classification is now >10 years old. Although its fundamental principle (two criteria required out of three) is still valid, each of its three items (oligo-anovulation (OA), hyperandrogenism (HA), and polycystic ovarian morphology (PCOM)) needs to be updated. The definition of biological HA is still unresolved. The criteria used to define OA are insufficient. The definition of PCOM proposed in 2003 is now obsolete when using the latest generation of ultrasound machines. The serum anti-Müllerian hormone (AMH) assay seems increasingly to be an excellent substitute for follicular count and is likely to emerge as the official PCOM marker. A new consensus conference is urgently needed.