Comparison of Male and Female Pelves. One of the easiest ways to determine the sex of a skeleton is to look at the pelvic girdle. Male and female pelves differ in a number of ways. One way is the thickness and density of the pelvis. A male pelvis is thicker and heavier. Surprisingly, the wider female pelvis is lighter and less dense. The Ilia. The ilia of a male pelvis are more upright than the ilia of a female pelvis. The ilia of a female pelvis flare out laterally to give support for abdominal organs and during pregnancy the developing fetus. Pelvic inlet. The shapes of the male and female pelvic inlets differ too. This is the pelvic inlet, also known as the pelvic brim. The bony ring formed by the superior border of the pubic symphysis across the arcuate lines and the sacral promontory. In a male, the pelvic inlet is basically heart-shaped. Whereas in female, the pelvic inlet is more oval in shape. Pelvic Outlet. The pelvic outlet is the circular, bony inferior rim of the pelvis, defined by the pubic arch, ischium, sacrum and coccyx. In a male, the pelvic outlet is smaller because both of the iliac spines and the coccyx curve medially, jutting into the pelvic outlet. In a female, the pelvic outlet is larger because the iliac spines and the coccyx extend inferiorly, minimally entering the pelvic outlet. Pelvic Outlet with Fetal Skull. The female pelvic inlet and outlet are more spacious, which facilitates child birth. When we tried to pass this model of a fetal skull through a male pelvic girdle, it can't fit through the pelvic outlet, partially because the ischial spines and the coccyx are in the way. When we try to pass the model of the fetal skull through the female pelvis, you can see that the flat sacrum and coccyx, along with the open pelvic inlet and outlet, permit its passage through the pelvic outlet. Greater Sciatic Notch. In a male pelvis, the angle of the greater sciatic notch is sharper than in the female pelvis. In a female pelvis, the angle of the greater sciatic notch is wider. Pubic Arch. Finally, the angle of the pubic arch is much sharper in a male pelvis than in a female pelvis. In a female pelvis, the angle of the pubic arch is wider. Let's review the differences found between male and female pelves. Ilia. Pelvic inlet. Pelvic outlet. Greater sciatic notch. Pubic arch.