When I last looked, you could give a blanket consent or select consent options for a list of organs, including 'tissue'.
I have given my consent for donation of all the named organs, but specifically excluded 'tissue'. It may mean that somebody loses out on, I dunno, skin graft, or some research. But no tissue will be taken from my reproductive system, for donation or for research. Not ovarian tissue, not uterine tissue. My dh knows how I feel and is fully behind me on this.
(At the time I registered my consent he thought I was being melodramatic. The potential situation I was describing was so ridiculously implausible. He is now fully Team Terf.)