Part I: Polycystic ovary syndrome: Challenges and controversies 1. Defining PCOS: A syndrome with an intrinsic heterogeneous nature HECTOR F. ESCOBAR-MORREALE 2. Secondary PCOS: Well-defined causes, leading to the PCOS phenotype ALESSANDRA GAMBINERI, CAROLINA CECCHETTI, PAOLA ALTIERI, DANILO RIBICHINI, VALENTINA LO PREIATO, FLAMINIA FANELLI, AND UBERTO PAGOTTO 3. Developmental origins of polycystic ovary syndrome: Everything starts in utero DAVID H. ABBOTT, EMILY P. GREINWALD, AND JON E. LEVINE 4. The multifarious role of insulin in PCOS: From pathophysiology to therapeutic management PAOLO MOGHETTI 5. The pathogenic role of androgen excess in PCOS DUARTE PIGNATELLI, SOFIA S. PEREIRA, AND ELENI KANDARAKI 6. Intrinsic abnormalities of adipose tissue and adipose tissue dysfunction in PCOS P.M. SPRITZER, B.R. SANTOS, T.M. FIGHERA, L.B. MARCHESAN, AND S.B. LECKE 7. Diet and exercise in the management of PCOS: Starting from the basics GEORGIOS K. MARKANTES, GINA TSICHLIA, AND NEOKLIS A. GEORGOPOULOS 8. Targeting metabolism in the management of PCOS: Metformin and beyond SEDA HANIFE OGUZ, SULEYMAN NAHIT SENDUR, UGUR UNLUTURK, AND BULENT OKAN YILDIZ 9. Combined oral contraceptives: Why, when, where? ATHANASIOS ANTONIOU-TSIGKOS, KONSTANTINA PASTROMA, ELENI MEMI, NIKOLAOS VRACHNIS, AND GEORGE MASTORAKOS 10. Targeting infertility in PCOS: Unfolding "Ariadne's thread MARIANO MASCARENHAS AND ADAM H. BALEN 11. Inositols and other supplements in the management of PCOS VITTORIO UNFER, GIOVANNI MONASTRA, MARCO TILOTTA, GIANPIERO FORTE, AND SIMONA DINICOLA 12. Polycystic ovary syndrome and nonalcoholic fatty liver disease CARMEN EMANUELA GEORGESCU 13. Cardiometabolic risk in women with PCOS ENRICO CARMINA Part II: PCOS and pregnancy: Current concepts? 14. Endocrine-disrupting chemicals and PCOS: A novel contributor in the etiology of the syndrome EVANTHIA DIAMANTI-KANDARAKIS, OLGA PAPALOU, AND ELENI KANDARAKI 15. Long-term health in women of age more than 40years with polycystic ovary syndrome ELENI ARMENI AND IRENE LAMBRINOUDAKI 16. Vitamin D metabolism in polycystic ovary syndrome (PCOS) FLAVIA DI BARI AND SALVATORE BENVENGA 17. The challenging role of antiandrogens in the management of polycystic ovary syndrome KASIANI PAPADIMITRIOU, PANAGIOTIS ANAGNOSTIS, AND DIMITRIOS G. GOULIS 18. PCOS in adolescence: Pathophysiology, diagnostic challenges, and therapeutic controversies NICOLAS CRISOSTO