Follicle number per ovary (FNPO) ≥20 diagnosed 94% of PCOS patients and correlates with hyperandrogenism and metabolic disturbances, but requires adjustment for ultrasound technology and operator proficiency.
Does ultrasonographic evaluation improve the diagnosis and prediction of reproductive-metabolic dysfunctions in women with polycystic ovary syndrome?
Ultrasonographic markers such as follicle number per ovary and ovarian volume are central to PCOS diagnosis, while emerging features like follicle distribution pattern and stromal area ratio show potential for predicting metabolic risk but need further standardization.
Effect estimate: FNPO > 20 threshold had 94% prevalence in PCOS patients (diagnostic value)
Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder with variable clinical presentations, posing diagnostic challenges. This article presents a narrative review of the pertinent literature regarding the ultrasound parameters for the diagnosis and prediction of reproductive-metabolic dysfunctions in PCOS. A comprehensive search was conducted in PubMed and Embase databases for articles published in English from inception until 2025 using keywords and phrases including ‘polycystic ovary syndrome,’ ‘ultrasound,’ ‘ovarian volume,’ ‘antral follicle count,’ ‘follicle distribution pattern,’ ‘ovarian stroma,’ and ‘Doppler indices.’ Inclusion criteria comprised studies addressing diagnostic ultrasound markers for PCOS and their association with reproductive and metabolic outcomes. A review of the existing studies in this area showed that follicle number per ovary (FNPO) remains a core diagnostic marker for PCOS. The Rotterdam criteria define PCOM as ≥ 12 antral follicles per ovary; however, updated guidelines recommend thresholds of ≥ 20–25 to accommodate higher-resolution imaging. FNPO correlates strongly with hyperandrogenism and metabolic disturbances but requires consideration of ultrasound technology and operator proficiency for interpretation. Ovarian volume (OV) > 10 mL has been classically used, though ethnicity- and age-specific cutoffs have been proposed. OV correlates variably with reproductive and metabolic features. Follicle Distribution Pattern (FDP): Two main patterns—peripheral cystic pattern (or “string of pearls”) and general cystic pattern —reflect differences in follicle arrangement that are linked to endocrine profiles. FDP is not yet formally included in diagnostic criteria due to heterogeneity in associations and classification. Ovarian stromal area/ovarian area (SAOA) ratio: a higher SAOA ratio (> 0.32) suggests increased stroma proportion seen in PCOS and is associated with androgen excess. Doppler Indices (RI and PI) reveal changes in vascular resistance and pulsatility in ovarian and uterine arteries in PCOS. Lower RI and PI values typically indicate increased stromal vascularization, aiding diagnosis, though not yet routine clinically. Future research should prioritize prospective, multiethnic studies to establish age- and race-specific diagnostic and predictive thresholds. It is suggested that in future studies, the power of various sonographic markers for detecting and predicting metabolic disorders associated with PCOS be evaluated using artificial intelligence-equipped devices.
Pourkhani et al. (Mon,) conducted a review in Women with polycystic ovary syndrome (PCOS) diagnosis considering clinical and biochemical features including hyperandrogenism, menstrual irregularities, and ovarian morphology by ultrasound. Ultrasonographic assessment of follicle number per ovary (FNPO)/antral follicle count (AFC), ovarian volume (OV), follicle distribution pattern (FDP), stromal area/ovarian area ratio (SA/OA), and Doppler indices (RI and PI) vs. Standard diagnostic criteria or other ultrasound markers was evaluated on Diagnostic sensitivity and specificity of ultrasound markers for PCOS diagnosis and prediction of reproductive-metabolic dysfunctions (FNPO > 20 threshold had 94% prevalence in PCOS patients (diagnostic value)). Follicle number per ovary (FNPO) ≥20 diagnosed 94% of PCOS patients and correlates with hyperandrogenism and metabolic disturbances, but requires adjustment for ultrasound technology and operator proficiency.