The principal differences between male and female true and false pelvis include:-

http://en.wikipedia.org/wiki/Pelvis

The female pelvis is larger and broader than the male pelvis which is taller, narrower, and more compact.
The female inlet is larger and oval in shape, while the male sacral promontory projects further (i.e. the male inlet is more heart-shaped).
The sides of the male pelvis converge from the inlet to the outlet, whereas the sides of the female pelvis are wider apart.