The scientific, theological, legal, and ethical ramifications of the abortion issue are vexed. The practical issue is straightforward.
Women and girls have a right to control their own bodies, including, and especially, deciding whether or not to have a child. This right gets problematic only when a zygote has become an embryo and then a fetus and then a fetus developed enough that it is close to a baby: a human person with rights.
In the rough way reflected in Roe v. Wade, it is late-term abortion that is problematic and possibly evil, and the social policy for avoiding this potential evil is — obviously — to discourage late-term abortions.
One way to do that would be the puritan way of allowing as legitimate only sexual intercourse where reproduction is an acceptable, if not necessarily desired, outcome. But as a disreputable Shakespeare character correctly and rhetorically asks a far more respectable character, "Does your worship mean to geld and splay all the youth of the city?" For, otherwise, "Truly, sir, in my poor opinion, they will to't then."
And if "the youth" and a whole bunch of other demographics "will to it" and do it (and we will), then the ethical policy is to strongly encourage contraception and, when contraception fails — or people are unthinking or careless or brutally criminal and commit a rape: when a desperately unwanted pregnancy is a fact, the policy should be to facilitate early abortion.
Q.E.D. for abortion as an immediate practical matter of social policy. After we have widespread and effective contraception, after condom-use becomes a cultural norm (or a more elegant device or pharmaceutical regime is invented), after abortion becomes truly legal, readily available, safe, and rare — then we can worry about abortion's very real philosophical complexities.