Characteristics of different phenotypes of polycystic ovary syndrome based on the Rotterdam criteria in a large-scale Chinese population

Objective To analyse the phenotypic spectrum of polycystic ovary syndrome (PCOS) and determine the association between metabolic, hormonal and new ultrasonographic criteria. Design Clinical cross-sectional study. Setting University teaching hospital. Population A total of 804 Chinese women, among whom 719 cases were diagnosed as PCOS based on the 2003 Rotterdam criteria. Eighty-five women with regular menstrual cycles and without hyperandrogenism were recruited as controls. Methods PCOS patients were divided into four subgroups: (i) oligo- and/or anovulation (O), hyperandrogenism (H), and polycystic ovary morphology (P); (ii) O + H; (iii) H + P; and (iv) O + P. Main Outcome Measurements Clinical history, ultrasonographic (ovarian follicle number and volume), hormonal and metabolic parameters. Results The composition of the two new phenotypes created by the European Society for Human Reproduction and Embryology/The American Society for Reproductive Medicine (ESHRE/ASRM) 2003 was 65.6% (O + P and H + P). BMI and F-G scores were highest in the O + H + P group and lowest in O + P and controls. Serum testosterone concentrations and insulin resistance were highest in cases with O + H + P and O + H, intermediate in cases with H + P, and lowest in cases with O + P and controls. The prevalence of metabolic syndrome in the five groups was 28.5% (O + H + P), 25.5% (O + H), 8.3% (H + P), 7.2% (O + P) and 3.5% (controls), respectively. Conclusions Nonclassic phenotypes for PCOS (O + P, H + P and O + H + P) were more frequent than the classic phenotype (O + H). The nonhyperandrogenic PCOS phenotype (O + P), one of the new phenotypes created by the Rotterdam criteria, may represent a form of PCOS associated with milder metabolic profile compared with the other phenotypes.