Sorry, yeah, I realize I was proposing a reductio ad absurdum as a thought experiment. And yes, I do think that eventually they will get to that point, but my real point was that "time since conception" is not a great metric for a legal line to draw, it's merely a convenient one.

I think personally, as a cis white dude with no stake in the matter, if we had to draw a line for terminations without a specific reason, we should put it somewhere around 6 months with medical exceptions. Developmental problems often don't show up until fairly late, and I think that things like Down syndrome, major uncorrectable development abnormalities or genetic diseases or other quality-of-life issues are perfectly valid reasons for a pregnancy termination. But that's a huge mire to get sunk into and each additional rule would require debates.

Governments would have to be willing to take all of them as wards of the state. Before that, we would have to make sure it was just as safe as an abortion. After that, we would have to consider if this mother has a right to not allow this lump or cells to not grow into a full grown human who has to grow up as a ward of the state.

All of these questions apply at 6 months or whatever arbitrary date you set. Birth is a more dangerous and damaging procedure than abortion. If forcing the test tube baby extraction could be disallowed for danger, why isn't forced birth?