The Polycystic Ovary Syndrome (PCOS) is a clinical condition characterized by chronic anovulation, insulin resistance, and hyperandrogenism, affecting 6–10% of women in reproductive age. Its etiology is complex, heterogeneous, and not completely understood. Accumulating evidence suggests that genetic, endocrine, metabolic, and environmental aspects are involved in determining the syndrome.

Recent data showed that insulin resistance and secondary hyperinsulinemia play an important role in hyperandrogenism, anovulation or irregular cycles, and metabolic alteration in both lean and obese patients with PCOS. The current therapy aims to improve insulin-resistance, to reach a reduction of compensatory hyperinsulinemia and then improve metabolic and ovulatory features in patients with PCOS. According to recent guidelines, insulin-sensitizer drugs are the first-line therapy in women with metabolic abnormalities and irregular cycle with the purpose to improve fertility, whereas a lifestyle change with weight loss and physical activity is the first step in overweight and obese PCOS patients.

This special issue aims to publish groundbreaking researches that may open new scenarios and change the perspective of the topic. This concept will not be limited to clinical work about pharmacologic treatments, but it will involve especially basic science (immunology, cell biology, genetics, and epigenetics) to unravel new pathways to follow for the future management of PCOS and to improve our current knowledge of its etiology. Space will also be given to multidisciplinary contributions in order to investigate the impact of PCOS treatments on quality of life, psychological well-being, and sexuality.

Potential topics include but are not limited to the following:

• Diagnostic criteria and phenotypes of PCOS
• Anovulation in women affected by PCOS
• Hyperandrogenism in PCOS patients
• Insulin resistance in PCOS patients
• Oocyte quality and ovarian reserve in PCOS patients
• Infertility and subfertility cofactors in women affected by PCOS
• Medical treatments for PCOS
• Treatment of infertility in PCOS patients