Clinical manifestations of polycystic ovary syndrome
Prevalence
The prevalence of PCOS is 6-15% of women in the reproductive age group based on the current diagnostic criteria such as the National Institutes of Health criteria (1990) and the Rotterdam criteria (2003) (1, 3).
The Androgen Excess and PCOS Society criteria (2006) defined PCOS as a fulfilling hyperandrogenism (clinical and/ or biochemical) and ovarian dysfunction (oligoanovulation and/ or polycystic ovaries) after the exclusion of related disorders (30). Henceforth, the most encompassing criteria with the largest group of PCOS phenotypes will be the Rotterdam criteria (2003) (30).Spectrum of disease
The diagnostic criteria will therefore result in differing permutations of phenotypes observed in women with PCOS (Table 42.1). Importantly, although endocrine and metabolic disturbances such as obesity, insulin resistance, and dyslipidaemia are associated with PCOS, the current diagnostic criteria do not take these factors into consideration. Thus, the spectrum of PCOS phenotypes only include women with androgen excess who are disturbed by excessive body and facial hair and/or women with reproductive issues such as irregular menstrual cycles and anovulation trying to conceive or with a desire to have regular menstrual cycles.
Ethnic differences in women with polycystic ovary syndrome
Ethnic differences appeared to exert significant influences on the prevalence of PCOS based on the current diagnostic criteria. This is especially so in the clinical presentation and definition of hirsutism in East Asian women (Chinese, Japanese, Korean, Thai) when compared to Caucasian and Middle Eastern women as it is noted that the modified Ferriman-Gallwey (mFG) score is lower in East Asian women (4). Indeed, the prevalence of PCOS among the Asian populations has been reported to vary from 5.6% in the Southern Chinese population (31), 5.7% in Thai women (32), and 6.3% in Sri Lankan women (33), to 14.3% in Iranian women (34).
Even in studies on Caucasian subjects, the prevalence of PCOS ranges from 6% to 15% (3). These differences are likely to be contributed to by ethnic differences. South Asian and Middle Eastern women with PCOS are also known to have a higher prevalence of obesity, diabetes, and metabolic diseases whereas East Asian women are less likely to be afflicted (1). Further work is still required to determine the impact of ethnicity on the reproductive, endocrine, and metabolic disturbances in women with PCOS.Disease evolution and effects of reproductive ageing
The effect of reproductive ageing in women with PCOS remains poorly understood. However, studies have shown that there is an improvement in the regularity of menstrual cycles with reproductive ageing in women with PCOS (35, 36). Serum testosterone levels decreased in women with PCOS from the third to the fifth decades. Additionally, with age, ovarian size and morphology was also noted to be improved (1). The PCOS phenotype appears to change with ageing, suggesting an amelioration of the phenotype and ovarian dysfunction as indicated by the increase in number of regular menstrual cycles, decrease in serum androgen levels, and decrease in insulin resistance (37). There are still limited data on the long-term fecundity and the precise age of menopause although there are studies reporting that women with PCOS may experience menopause at a later age (38, 39). Long-term, multicentre cohort studies are needed to understand if there is a menopausal phenotype for women with PCOS and the associated long-term health consequences in these women.
Table 42.1 Possible phenotypes of PCOS
| Clinical manifestation | I Possible phenotypes for PCOS | |||||||||
| Hyperandrogenaemia | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 0 |
| Hyperandrogenism (hirsutism) | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 |
| Menstrual irregularities | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 |
| Polycystic ovarian morphology on ultrasound | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 1 |
| Diagnostic criteria | ||||||||||
| NIH Criteria 1990 | + | + | + | + | + | + | ||||
| Rotterdam Criteria 2003 | + | + | + | + | + | + | + | + | + | + |
| Androgen Excess Society/PCOS Society 2006 | + | + | + | + | + | + | + | + | + | |
1= present 0 = not absent.
Source data from Azziz R, Carmina E, Dewailly D, Diamanti-Kandarakis E, Escobar-Morreale HF, Futterweit W, Janssen OE, Legro RS, Norman RJ, Taylor AE, Witchel SF; Task Force on the Phenotype of the Polycystic Ovary Syndrome of The Androgen Excess and PCOS Society, The Androgen Excess and PCOS Society criteria for the polycystic ovary syndrome: the complete task force report. Fertil Steri12009;91(2):456-88.