Answer:
"Facts" are such slippery things in our culture. It is like the word "fact" now means "my strongly held opinion backed by soundbytes I heard from those who think like I do."
Here are some facts, from someone (me) who finds proponents on either side to be rather strident and silly.
1. If you are to be against abortion, it helps to be for birth control. Otherwise you are like someone against people being fat, but wishing to outlaw all diets and exercise programs.
2. If you are to be against abortion, it helps not to be so absolute. In other words, you are never going to convince someone that it is appropriate for a 14 year old girl to give birth to a retarded child placed there by her rapist father when doing so will result in her sure and certain death. At the least, saving the mother's life should be an exception. And you may wish to consider "incest" or "rape" as exceptions, too. You'll sound more compassionate.
3. If you are to be against abortion, it helps to be for things that reduce the need for it. This is broad, and includes things from sex education in schools (and I know some of that needs to be reformed) and regulations on adoption. Our adoption laws are insane, and only the rich can afford to adopt nowadays. Let us witness you fighting that battle, and your other battle will seem more credible.
4. If you are to be against abortion, do not overstate. The death of six million Jews, and another 8 million gypsies, slavs, etc., was indeed a "holocaust". That's why we call it that. But a 14 year old girl made pregnant by her dad and getting an abortion - well, that's a lot of things, tragic amongst them, but "holocaust" it is not. And guess what? 400 14 to 28 year olds getting abortions for their personal reasons is not a "holocaust". It's just something you don't like. But as they probably didn't like it either, you're even.
5. Know this - no sane person is "for" abortion. All good people on all sides wish it were not needful. Advocate for changes in society that make the need less. Advocate for programs and plans that help prevent unwanted pregnancies. Advocate for things that make the choice of adoption easier. Advocate for reasonable restrictions and regulations on abortions that are for the safety of all. And advocate for those intelligent exceptions - saving the mother's life, rape and incest.