Follicle number, not assessments of the ovarian stroma, represents the best ultrasonographic marker of polycystic ovary syndrome

Objective: To compare the diagnostic potential of ultrasonographic markers of ovarian morphology, used alone or in combination, to predict polycystic ovary syndrome (PCOS). Design: A diagnostic test study using cross-sectional data collected from 2006-2011. Setting: Academic hospital and clinical research unit. Patient(s): Eighty-two women with PCOS and 60 healthy female volunteers. Intervention(s): None. Main Outcome Measure(s): Follicle number per ovary (FNPO), ovarian volume (OV), follicle number per single cross-section (FNPS), follicle distribution pattern, stromal area, ovarian area, stromal-to-ovarian area ratio (S: A), and stromal index (SI). Result(s): Follicle number per ovary best predicted PCOS (R-2 = 67%) with 85% sensitivity and 98% specificity, followed by OV (R-2 = 44%), and FNPS (R-2 = 36%). Neither S: A nor SI had predictive power for PCOS. In combination, FNPO+S:A and FNPO+SI most significantly predicted PCOS (R-2 = 74% vs. 73%, respectively). The diagnostic potentials of OV and FNPS were substantially improved when used in combination (OV+FNPO, R-2 = 55%). Conclusion(s): As a single metric, FNPO best predicted PCOS. Although the addition of S: A or SI improved the predictive power of FNPO, gains were marginal, suggesting limited use in clinical practice. When image quality precludes a reliable estimation of FNPO, measurements of OV+FNPS provide the next closest level of diagnostic potential. (Fertil Steril (R) 2014; 101: 280-7. (C) 2014 by American Society for Reproductive Medicine.)