Here are three translations; two use the word "miscarriage," while the third uses the word "abort." Even for those translations which don't use this strong language, how do you account that killing a living person is manslaughter, but causing the death of the fetus is simply a misdemeanor (paid by fine)?
I used the most up to date translations after biblical scholars debated the translations from Hebrew to Aramaic to Greek to Latin to whatever. There have always been errors in translations and I believe the oldest known version of the Septuagint has a notation in the margin by an editor raking the then copier over the coals over mistranslating a word and changing the meaning of the passage.
I believe the whole issue comes down to the translation of a few words:
Yeled and Yasa
A word's meaning in any language is determined in two steps. We learn a word's range of meaning--its possible definitions--inductively by examining its general usage. We learn its specific meaning within that range by the immediate context.
The relevant phrase in the passage, "...she has a miscarriage...," reads w?yase û ye ladêhâ in the Hebrew. It's a combination of a Hebrew noun, yeled, and a verb, yasa, and literally means "the child comes forth." The NASB makes note of this literal rendering in the margin.
The Hebrew noun translated "child" in this passage is yeled (yeladim in the plural), and means "child, son, boy, or youth." It comes from the primary root word yalad, meaning "to bear, bring forth, or beget." In the NASB yalad is translated "childbirth" 10 times, some form of "gave birth" over 50 times, and either "bore," "born," or "borne" 180 times.
The verb yasa is a primary, primitive root that means "to go or come out." It is used over a thousand times in the Hebrew Scriptures and has been translated 165 different ways in the NASB--escape, exported, go forth, proceed, take out, to name a few. This gives us a rich source for exegetical comparison. It's translated with some form of "coming out" (e.g., "comes out," "came out," etc.) 103 times, and some form of "going" 445 times.
What's most interesting is to see how frequently yasa refers to the emergence of a living thing:
Genesis 1:24 "Then God said, 'Let the earth bring forth living creatures after their kind: cattle and creeping things and beasts of the earth after their kind'; and it was so."
Genesis 8:17 [to Noah] "Bring out with you every living thing of all flesh that is with you, birds and animals and every creeping thing that creeps on the earth...."
Genesis 15:4 "This man will not be your heir; but one who shall come forth from your own body...."
Genesis 25:25-26 "Now the first came forth red, all over like a hairy garment; and they named him Esau. And afterward his brother came forth with his hand holding on to Esau's heel, so his name was called Jacob."
1 Kings 8:19 "Nevertheless you shall not build the house, but your son who shall be born to you, he shall build the house for My name."
Jeremiah 1:5 "Before I formed you in the womb I knew you, and before you were born I consecrated you; I have appointed you a prophet to the nations."
2 Kings 20:18 "And some of your sons who shall issue from you, whom you shall beget, shall be taken away; and they shall become officials in the palace of the king of Babylon."
As you can see, it's common for yasa to describe the "coming forth" of something living, frequently a child. There is only one time yasa is clearly used for a dead child. Numbers 12:12 says, "Oh, do not let her be like one dead, whose flesh is half eaten away when he comes from his mother's womb!"
Note here, that we don't infer the child's death from the word yasa, but from explicit statements in the context. This is a still-birth, not a miscarriage. The child is dead before the birth ("whose flesh is half eaten away"), and doesn't die as a result of the untimely delivery, as in a miscarriage.
Yasa is used 1,061 times in the Hebrew Bible. It is never translated "miscarriage" in any other case. Why should the Exodus passage be any different?
Clues from the Context
This inductive analysis shows us something important: Nothing about the word yasa implies the death of the child. The context may give us this information, as in Numbers 12:12, but the word itself does not.
This leads us to our next question: What in the context justifies our assumption that the child that "comes forth" is dead? The answer is, nothing does. There is no indication anywhere in the verse that a fine is assessed for a miscarriage and a more severe penalty is assessed for harming the mother.
This becomes immediately clear when the Hebrew words are translated in their normal, conventional way (the word "further" in the NASB is not in the original):
"And if men struggle with each other and strike a woman with child so that the child comes forth, yet there is no injury, he shall surely be fined as the woman's husband may demand of him; and he shall pay as the judges decide. But if there is any injury, then you shall appoint as a penalty life for life...."
The text seems to require a fine for the premature birth, but injury to either of the parties involved incurs a more severe punishment. Millard Erickson notes that "there is no specification as to who must be harmed for the lex talionis [life for life] to come into effect. Whether the mother or the child, the principle applies."
Gleason Archer, Professor of Old Testament and Semitic Studies at Trinity Evangelical Divinity School, concludes:
"There is no ambiguity here, whatever. What is required is that if there should be an injury either to the mother or to her children, the injury shall be avenged by a like injury to the assailant. If it involves the life (nepes) of the premature baby, then the assailant shall pay for it with his life. There is no second-class status attached to the fetus under this rule; he is avenged just as if he were a normally delivered child or an older person: life for life. Or if the injury is less, but not serious enough to involve inflicting a like injury on the offender, then he may offer compensation in monetary damages..."