Abstract
Background: Sexual dimorphism in pelvic anatomy is a critical area of study due to its implications in childbirth, pelvic surgery, and biomechanical stability. Differences between male and female pelvic structures reflect evolutionary adaptations, hormonal influences, and functional demands. This study evaluates transverse and sagittal pelvic diameters, pelvic angles, and pelvic indices in a diverse population to assess gender-based differences.
Methods: A total of 300 participants (200 females and 100 males) were included in the study. Measurements were taken for transverse pelvic diameters (inlet, midplanes, and outlet), sagittal diameters, pelvic angles (sacral slope, pelvic inclination, and subpubic angle), and pelvic indices. Statistical analysis was conducted to determine the presence of significant sexual dimorphism across these parameters.
Results: Females exhibited significantly larger transverse pelvic diameters compared to males across all planes: inlet (12.839 vs. 11.403 cm, p = 0.000), midplane 1 (11.485 cm vs. 10.387 cm, p = 0.000), midplane 2 (9.835 cm vs. 8.857 cm, p = 0.000), and outlet (9.221 cm vs. 9.012 cm, p = 0.015). Sagittal pelvic diameters were also consistently larger in females, with significant differences at the inlet (12.039 cm vs. 10.313 cm, p = 0.000), midplane 1 (11.532 cm vs. 9.942 cm, p=0.000), and midplane 2 (11.065 cm vs. 10.302 cm, p=0.000). Sacral slope and pelvic inclination were significantly higher in females (sacral slope: 36.727° vs. 36.204°, p = 0.000; pelvic inclination: 63.376° vs. 61.384°, p = 0.001), suggesting adaptations for pregnancy and parturition. However, no significant gender-based differences were observed in the subpubic angle or pelvic indices at the inlet, midplanes, or outlet except for a lower mean pelvic index in females at the outlet (p = 0.000).
Conclusion: The study confirms significant sexual dimorphism in pelvic anatomy, particularly in transverse and sagittal diameters, sacral slope, and pelvic inclination. These findings highlight the evolutionary and functional adaptations of the female pelvis for childbirth and its dynamic interplay with spinal mechanics.
Keywords: Pelvic dimensions, sexual dimorphism, transverse diameters, sagittal diameters, sacral slope, pelvic inclination, coefficient of dimorphism, gender differences.
