Samuel Harry Myers, Michele Russo, Simona Dinicola, Gianpiero Forte, Vittorio Unfer
PCOS is routinely assessed using the Rotterdam criteria, which consider hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. These criteria have faced criticism in recent years. These criteria yield four distinct phenotypes, three of which (A, B, and C) demonstrate hyperandrogenism, whilst the fourth, Phenotype D, does not. It is questioned whether they share the same etiopathogenesis, and whether alterations in insulin-like growth factor 1 or gonadotrophin levels could be responsible for Phenotype D. Phenotypes A, B, and C seem to be associated with insulin resistance, especially as it pertains to hyperandrogenism, while this is less likely with Phenotype D. It has been suggested that this finding could trigger a reclassification of the PCOS criteria. Tailored therapies are required, as a lack of specific treatments exist for phenotype D.