It depends. By which moral standard? By strictly Biblical standards, occurring to the society abroad at the time and context of the composition of Scripture, abortion has no moral valence beyond “destruction of property” whatsoever (more on this below). By modern Western standards, there are ethical complications when the fetus is a viable baby. This standard, however, is unjust in so far as viability depends heavily upon the standard of medical care in the pregnant woman’s community. A miscarriage in rural El Salvador might easily be an (otherwise uncomplicated) premature delivery in Santa Barbara. This is why I wish so fervently that the vast energies and resources applied by good Christians to America’s “pro” life movement would instead devote them to providing better social services to needy communities around the world.
To the extent “anti-abortionism” is a major cause among American evangelicals, it is a much more modern concept with no basis in Scripture. In the few cases when premature termination of a pregnancy is mentioned in the Bible, it is neither called a murder nor is it punished as if it were. Indeed, in the Ordeal of the Bitter Waters, Israelite temple priests are commanded BY GOD to subject a wife suspected of pregnancy by infidelity to a procedure intended to abort an illegitimate pregnancy.
The Bible makes no mention, ever, that a human life “begins” at “conception” (itself a vernacular word with no clinical meaning). Moreover, in every verse describing the beginning of a human life, the moment specified is BIRTH, when the newborn draws its first breath of LIFE. Indeed, this is precisely the language used in Genesis to describe God’s vivification of Adam. God formed the first man fully out of clay (which is interesting in that he alone among the creatures required ingredients for assembly) but he was not alive until God blew the breath of life into his nostrils. My understanding is this interpretation is still common among Jewish communities. Life begins with the first breath.
In any case, the concept of the immorality of abortion is not Biblical. The Catholic Church adopted it as doctrine in the 1300s. And American evangelicals who argue against ANY abortion whatsoever suffer the same problem of like-minded Catholics. If “Morality” is absolute, objective, unchanging, and explicitly delineated in Scripture, then abortion neither is, nor can it be interpreted as, immoral. On the other hand, if abortion is immoral, then “Morality” is a spoken and unspoken code of behavior we all agree to (albeit inconsistently and imperfectly) and strive to abide (just as inconsistently and imperfectly) drawing whatever information and inspiration from God we can glean from Scripture, dogma, and examples of piety throughout history and in our community.
Personally, I hold that preventing a woman’s access to any abortion before the fetus is a viable baby is without question LESS moral than granting that access. I have a long list of reasons for this opinion and am happy to discuss them, but I am aware mine is a minority and unpopular perspective here and don’t want to deliberately spark brush fires needlessly. I merely wanted to lay out that the argument can be made by someone while still considering themselves a true Christian.