Embryo

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.

Moria has a review and doesn't like it. TCM has an overview.