Libertarians for Life (l4l.org) does a wonderful job at arguing for prenatal rights from an entirely secular an libertarian viewpoint. They are very thorough; any arguments I'd use could be found there.
Some people believe the two terms are not synonymous, and most logisticians would likely agree.
"True" pro-lifers perhaps believe in: 1) anti-abortion in all cases, even in the case of rape, incest, woman's health, etc., 2) no dealth-penalty, and 3) anti-war. Each of these examples is a man killing another man.
I have never met anyone like this. Most people who claim to be "pro-life" are only against the first option.
An anti-abortionist would simply be someone who is anti-abortion (in all cases), or perhaps only against abortion when used as a contraceptive, but believes in the death penalty and/or in war.
More people are "anti-abortionists" and fewer people are "pro-lifers," respectively. Also, someone can be pro-choice, but anti-abortion! Wrap your head around that one.
Oh, and why is incest so often lumped in with rape? If the incest wasn't consentual, it falls under "rape", no other category needed. If it was consentual, what's the problem? Birth defects? That falls under "fetal deformity".
Incest packs more punch than "fetal deformity." Also, children who are born of relatives won't always be deformed. The parents who later find out they are related may simply want to terminate the pregnancy.
Again....children conceived from two related people will not necessarily be deformed, so the "fetal deformity" concept alone is bankrupt.
AND when arguing FOR abortions in the rare case category, "fetal deformity" would not go over well with the pro-lifers. "So what a baby is deformed, we should just automatically get rid of it?" My argument would be, "Well yes in the case of incest!"