I've always thought these passages seemed like an embarrassingly flimsy way to make an argument about whether a fetus is a person.
Obviously, a person is, at the very least, "under construction" in the womb. We don't need a Bible passage to tell us that. But what these passages do not provide is any statement on whether God actually considers a person "complete" while they are still in the womb. Instead, all these verses really say is that God is prescient - not that God considers a fetus to be a full person.
By contrast, one Bible verse that does seem to take a definitive stance on abortion is Numbers 5: 7:
"If she has made herself impure and been unfaithful to her husband, this will be the result: When she is made to drink the water that brings a curse and causes bitter suffering, it will enter her, her abdomen will swell and her womb will miscarry, and she will become a curse."
Seems like this is actually a direct command to commit abortion if the pregnancy is caused by infidelity - isn't it?
Obviously, this passage is fraught in it's misogyny, but it does seem like the most difinitive stance on abortion I've ever seen in the Bible, and seems like something that might sway some fundamentalists.
Do you have any thoughts on that?