**1. Introduction**

## **1.1. Definition**

Polycystic ovarian syndrome (PCOS) is characterized by endocrine and ovarian disorders that affect quality of life in women of reproductive age. In 1935, PCOS was first described by Stein and Leventhal with a description of seven women suffering from amenorrhea, hirsutism, and enlarged ovaries with multiple cysts [1, 2]. Some different criteria about the National Institute of Health (NIH), Rotterdam criteria, Androgen Excess Society and Polycystic Ovary Syndrome Society guidelines (AE-PCOS) are shown in **Table 1** [3–8].
