Don't be bullied by accusations of "lack of compassion!"

There is no "if" according to biology and embryology.
The "if" in that statement is rhetorical.
It is settled science that the preborn are fully human so that question has already been answered. So instead of calling it a fetus call it a human being and don't try to equate a human being to an organ. Guess what? To donate an organ a person has to make a choice but in abortion there is no choice on the part of the human being that is going to be killed for the so called benefit of the mother.

You are trying to read your presuppositions into the argument. It can't be simply a human being from your prospective because that hurts any argument for killing the human being.

Often the pro-infanticide side will talk about "fully developed" versus biologically and genetically human.

By what standard is a human "fully developed"? Is a 5 year old fully developed?
Should the mother of a 5 year old be compelled to donate her time, resources, life, and body so the 5 year old can survive?

To answer your question...

Even a teenager isn't a fully developed human. What a shoddy argument. May as well abort unruly children, right? They haven't developed yet, either.

Fantastic find. It's a very well thought out argument. The statement about how the rapist is the one who forced the child upon the woman is very powerful and correct. I hope this meme does well.