“I do wonder if it is biblical to extend “full” protection to a fetus? I.e. when a man hurts a pregnant woman, he’s expected to pay an eye for an eye & a tooth for a tooth. But if the unborn baby is killed, the price is not the same.”
I assume you are referring to Exodus 21:22-24, and there is definitely disagreement about what that text means, even among the translators:
NIV: If men who are fighting hit a pregnant woman and she gives birth prematurely but there is no serious injury...
NRSV: When people who are fighting injure a pregnant woman so that there is a miscarriage, and yet no further harm follows...
KJV: Exodus 21:22–24 If men strive, and hurt a woman with child, so that her fruit depart from her, and yet no mischief follow...
The question is does “serious injury/further harm/mischief” refer to the mother only or to mother and child. The Hebrew means simply “the children come out”, which would seem to agree with the NIV and (to a lesser extent) the KJV, rather than with the NRSV.
The commentaries I checked (Word, IVP Bible Background, Bible Knowledge, Expositor’s, Tyndale, MacArthur, Lange, Evangelical(Elwell), and Keil & Delitzsch) are split but lean toward the mother and child.
Elwell has this note: “The Hebrew word for miscarriage is not used here.” It is different word than is used when the context clearly indicates miscarriage (Exodus 23:26, Job 21:10, Hosea 9:14)
I think the best interpretation of the passage is that if there is no serious injury/further harm/mischief to either mother or baby, then there is a fine for striking them and causing the early labor. If there is harm to either, then lex talionis applies.
It is clear throughout several old testament passages that people were valued differently. For instance, reparations for accidentally killing a slave were lower than for a free adult jew. In such a context, looking at this passage, an unborn baby isn’t worth as much reparation as an adult jew — otherwise it would just be eye for an eye.