Embryo is a 1976 horror movie starring Rock Hudson, Barbara Carrera and Roddy McDowell. Remember Alraune? Similar concept, but there's more horror here. I saw this somewhere in a list of science fiction films but it seems to me to be a better fit for the horror category, which is where I'm putting it on my list.
It's in the public domain. You can see it via youtube or at FreeMoviesOnline.com:
As I try to watch it at that site it keeps stopping. When I push the play button it restarts from the beginning. Frustrating, and I'm not sure it's at all worth the effort.
Moria has a review and doesn't like it. TCM has an overview.