**1. Introduction**

Polycystic ovary syndrome (PCOS) is a common endocrinophaty disorder that affecting reproductive aged women [1]; it becomes frequently manifest during early reproductive age [2]. It is a heterogeneous disorder, with multiple reproductive, cosmetic and metabolic complexities which is characterized by dysfunction in ovulation and clinical or biochemical hyperandrogenism and the presence of polycystic ovarian morphology. It is the most common endocrine cause of infertility and increased the risk of adverse pregnancy outcome, metabolic syndrome, type 2 diabetes mellitus, and some carcinoma [2-5]. However, there is not a consensus on its definition [6]. At the first time, PCOS was described by Stein and Leventhal in 1935 [6] as the presence of bilaterally enlarged ovaries with multiple cysts in seven women with infertility, menstrual irregularity and hyperandrogenism [7]. The National Institutes of Health (NIH) in 1990 introduced NIH standard criteria in PCOS for applying in researches and clinics [3]. This definition relied on clinical or biochemical evidence of hyperandrogenae‐ mia (in the absence of adrenal hyperplasia and hyperprolactinemia and thyroid dysfunction) in combination of oligomenorrhoea or amenorrhea. Therefore, PCOS was diagnosed in the absence of an ultrasound appearance of polycystic ovaries morphology [8]. In 2003, a consen‐ sus workshop in Rotterdam in the Netherlands presented new diagnostic criteria [3]. Rotter‐ dam criteria describe PCOS as persistence of PCO and hyperandrogenism in women with normal menstrual cycles and especially women presenting with PCO and ovulatory disturb‐ ance without hyperandrogenism [9].

In 2009, the Androgen Excess and PCOS Society (AE-PCOS Society) introduced criteria for PCOS. Based on AE-PCOS Society criteria, PCOS should be define by the presence of hyper‐ androgenism (clinical and /or biochemical), ovarian dysfunction (ovulation disturbance and or polycystic ovary morphology), and the exclusion of other androgen excess or related

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disorders [10]. These criteria reflected differences in defining PCOS which could affect reporting, diagnosis and treatment of it.

#### **1.1. Epidemiology**

Despite PCOS being considered the most common endocrine disorder, the estimation of its prevalence is highly variable, ranging from 2.2% to 26.7% [11-13], due to differences in the presentation of PCOS phenotype methods [12]. In a study in Iran, a total of 646 reproductiveage women were assessed by Rotterdam, Androgen Excess Society, and NIH criteria, the prevalence of PCOS were 14.1%, 12%, and 4.8% respectively [14]. In a study from china, levels of luteinizing hormone and higher luteinizing hormone/follicle-stimulating hormone ratios were used for defining PCOS for 915 women in reproductive age, the results demonstrated 2.2 % prevalence [14]. In a study from china, levels of luteinizing hormone and higher luteinizing hormone/follicle-stimulating hormone ratios were used for defining PCOS for 915 women in reproductive age, the results demonstrated 2.2 % prevalence [11]. The prevalence based on NIH criteria in an unselected population black and white women in the southeastern United States were 3.4% and 4.7% respectively [15]. Using same criteria, the prevalence of PCOS was almost 6.5% between Caucasian and Greek women [16, 17].
