Anti-Personhood people love to cite Exodus 21:22. I've even seen atheists cite it for some strange reason! Ignoring the fact that the Bible is clearly not a reliable source, and that Christians consider Exodus binding only to Jews (even Jews don't accept all of it, like Exodus 21:17), I'l address why this should not be used. Anti-personhood people will generally usae a translation like this:
Exodus 21, v. 22 When men fight, and one of them pushes a pregnant woman and a miscarriage results, but no other damage ensues, the one responsible shall be fined according as the woman’s husband may exact from him, the payment to be based on reckoning. 23 But if other damage ensues, the penalty shall be life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burn for burn, wound for wound, bruise for bruise.
However, the original Hebrew does not mention a miscarriage. The verb used is "to go forth", a verb used elsewhere in the Bible to refer to a live birth. There is another verb that refers exclusively to a miscarriage, which is used elsewhere in the Bible. However, "to go forth" is ambiguous in this context. That's why it's clarified by "and no harm is done". If the baby is born and no harm is done, it can't be a miscarriage.
Yes, they are using a mistranslation of an obsolete section of a questionable source.
If two men are fighting and one hits a pregnant woman in the crossfire, causing her to give birth early, he must pay for her inconvenience. But if there is any harm (notice harm is not specified as to the mother), the man must pay eye for eye, tooth for tooth.