It is noteworthy that you have this gestationally-related sliding scale of worth, based on potential. It makes it sound as though you are relying on something extrinsic (time elapsed since conception) and something intrinsic (developmental level of the fetus) to decide how much value the fetus's life has.
You have something in common with the pro-choicers who think fetuses are "potential" humans (but think that fetuses have no worth in themselves) and something in common with the pro-lifers who think fetuses have worth (but think fetuses are more than merely potentially human).
You said that it becomes "More foolish" to abort a fetus as time elapses.
Why would it be more foolish?
Who would be the fool for the abortion taking place at that later time...the mother, the doctor, the fetus, society in general? Foolishness implies a person or people who are being foolish.
What standard of wisdom (non-foolishness) would be broken?
Strident pro-choicers see an antagonism between the fetus and the world the fetus would be born into.
In their minds a particular fetus has no worth to the world unless someone in the outside world determines the fetus has worth. (Like a non-aborting mother).
Oh, I forgot.
People who want to use the fetus/embryo for human experimentation and people who want to use parts of its body to cure other humans think the fetus/embryo has some worth to them. But it is a different type of worth.
Those people find the fetus/embryo human enough to help science, but NOT human enough to be allowed to live. They might say pro-lifers are too judgmental of others, but at the same time they are perfectly willing to do their own judging of the worthiness of the fetuses to live. They are far more meddlesome in others' lives than the right-to-lifers are. They aren't just taking a moral or a religious or a humanistic stand. They are playing God, controlling who gets to live and who must die.
Their sliding scale of value would be based on the uses they can find for the fetus/embryo.
With their sliding scale the fetuses and embryos with the higher value are more likely to be dismembered.
With your sliding scale the fetuses and embryos with the higher value are more likely to get to live.
It would be foolish to abort unto intentional death any fetus that could be delivered and survive (unless the life of the mother was somehow put a great risk by the attempted delivery)
I believe that it would be so foolish, that I would vote to make such abortions illegal.