Abstract
<title>Abstract</title> <p> <bold>Background</bold> Infertility impacts reproductive-age couples worldwide, with obesity—especially abdominal obesity—being increasingly recognized as a factor in female reproductive dysfunction. Alternative anthropometric measures beyond body mass index (BMI), such as the body shape index (ABSI), waist‒to-hip ratio (WHR), and body adiposity index (BAI), may provide a more complete assessment of body composition related to fertility; however, data directly comparing their discriminatory power in clinical settings remain limited. This study compared anthropometric parameters between fertile and infertile women to understand the relationship between body composition and infertility. <bold>Methods</bold> A cross-sectional study was conducted with 210 women divided into fertile (n = 105) and infertile (n = 105) groups at Konya City Hospital. The fertile participants achieved spontaneous pregnancy without chronic disease, whereas the infertile participants had unexplained infertility or ovulatory dysfunction. Anthropometric measurements were taken, and BMI, WHR, waist-to-height ratio (WHtR), ABSI, body roundness index (BRI), and BAI were calculated. Hormonal parameters and antral follicle counts were obtained for the infertile group. <bold>Results</bold> Hip circumference was significantly greater in infertile women (p = 0.028), whereas WHR and ABSI were significantly greater in fertile women (p < 0.001 for both). BAI was significantly greater in the infertility cohort (p = 0.007). In the ROC curve analysis, generalized obesity metrics (BMI, weight, height) and certain central indices (WC, WHtR, BRI) failed to demonstrate discriminative power (p ≥ 0.05). Conversely, novel and regional geometric indices demonstrated prominent predictive performance; the BAI yielded an AUC of 0.603 (95% CI: 0.527–0.680, p = 0.010), with an optimal cutoff of > 33.87. Owing to their inverse physiological distributions, the WHR and ABSI displayed significant inverse discriminative pathways for infertility status, yielding AUC values of 0.319 (95% CI: 0.247–0.491, p < 0.001; cutoff (≤ 0.80) and 0.356 (95% CI: 0.282–0.430, p < 0.001; cutoff (≤ 0.076), respectively. <bold>Conclusion</bold> Anthropometric measurements reflecting abdominal fat distribution—particularly the WHR, ABSI, and BAI—show significant associations with infertility beyond traditional BMI assessment. A comprehensive, multidimensional anthropometric evaluation, including multiple indices, is recommended for routine infertility assessment to improve risk stratification and diagnostic guidance. </p>