Introduction

Polycystic ovary syndrome (PCOS) is the commonest endocrine disorder in women of reproductive age as this syndrome may affect 5–10% of premenopausal women in Western countries (Franks 1995). Women with this syndrome may present with one, all, or any combination of menstrual irregularities, chronic anovulation, infertility, obesity, and hyperandrogenism. There is substantial heterogeneity of symptoms and signs among women with PCOS and different criteria have been used to confirm the diagnosis. Ultrasound assessment of ovarian morphology is considered to be essential and the gold standard for defining polycystic ovaries in Europe (Adams et al. 1986, Balen 1999). Characteristic ovarian morphology is not required in the American definition, which states that PCOS is the association of hyperandrogenism with chronic anovulation in women without specific underlying diseases of the adrenal or pituitary glands (Dunaif 1997).

Recently, a revised definition of PCOS was agreed and required the presence of two from the following three diagnostic criteria: (1) oligo- and/or anovulation; (2) clinical and/or biochemical features of hyperandrogenism; and (3) the presence of polycystic ovary (PCO) morphology (The Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group 2004). In recent years, transvaginal ultrasound has become the most commonly used diagnostic method for the identification of PCO. In order to make a diagnosis of PCO, >10 follicles of 2–10 mm in diameter and increased density of ovarian stroma (Adams et al. 1986) are required.