Geographical Variations in Polycystic Ovarian Morphology: Comparison of India- and United States-Based Women with Polycystic Ovary Syndrome

Background/Objectives: Geographical differences exist in the clinical presentation of polycystic ovary syndrome (PCOS). The degree to which ovarian morphology contributes to this variability is unknown. Methods: This study compared ovarian ultrasound features between women with PCOS residing in two geographical regions (India and the United States) using stored de-identified ultrasound scans from 331 women with PCOS. Sonographic markers of interest included follicle number per ovary (FNPO), follicle number per cross-section (FNPS), ovarian volume (OV), ovarian area (OA), stromal area (SA), and stromal-to-ovarian area ratio (S/A). Results: Most participants in both regions met the accepted criteria for polycystic ovarian morphology (India 87% vs. U.S. 83%). The U.S.-based group had a higher prevalence of follicle excess (41% in U.S. vs. 29% in India; p = 0.037), whereas the prevalence of ovarian enlargement was similar across groups (India 37% vs. U.S. 31%, p = 0.252). FNPS was higher in the U.S.-based group (p = 0.046), while the India-based group had higher OV (p = 0.010). SA and S/A did not differ between groups, albeit OA was slightly larger in women with PCOS from India (p = 0.022). Associations between ovarian morphology and menstrual cycle length (ρ = 0.16–0.25), hirsutism score (ρ = 0.19–0.23), and total testosterone (ρ = −0.33–0.42) were noted in both groups (p < 0.05). Conclusions: Some variation in ovarian morphology may exist across geographic regions. However, the degree of variability is unlikely to warrant regional definitions for polycystic ovarian morphology at this time.