Comparing the act of pleasuring yourself on your own to conception is just a grotesque misunderstanding of how biology works and it's offensive to hear that as an argument for being pro-choice. I'm pro-choice myself, but I have an incredibly low tolerance for ignorance when it comes to the subject of terminating lives.
On the topic of Gosnell, that's diddlying horrifying. Can't believe that it was able to operate so shadily.
I happen to be pro-life, but what Ultima Keyblade and others have been saying does have a purpose, Trag, even though it has been stated rather obtusely. I think everybody here agrees that the fetus is alive (correct me if I'm wrong, pro-choice'ers). The whole debate really basically boils down to deciding at which fairly arbitrary point we set the beginning of person-hood; i.e. the beginning of rights such as life. What the masturbation argument is meant to highlight is that arguing (like many pro-life'ers do) that anything with the potential to become human under the right circumstances deserves rights is an invalid argument, since things like gametes, or even certain other cells, could potentially become a person under the right circumstances. So there has to be an actual point of person-hood; potential is not the deciding factor. The pro-choice view draws the line at the development of certain physiological traits or features. Pro-life tries to trace it back further to genetic traits or features, generally. Either way, it's chemically arbitrary, though certainly not legally arbitrary. And like you said, it is an issue of human life, which is why people get so fired up and, frankly, unreasonable during debates about the topic.
But in the end what I stated above is the main issue of the debate. The two views follow pretty clearly: if the fetus is not a person, then a woman's right to do what she wants with her body is the greatest right at play, so abortion is morally acceptable because a woman can justifiably rid her body of foreign parasites; however, if the fetus is a person, then the woman's right to do what she wants with her body has to go up against the fetus' right to life, a contest most pro-choice supporters believe that the fetus wins, since the woman did consent to having sex knowing there was a (sometimes extremely minute) chance that a fetus could form (NOTE: this only applies in non-rape scenarios; rape is a whole other can of worms).
So while I heartily disagree with abortion, pro-choice people are not that much different than pro-life supporters. There really is only one small difference between the two, and it happens to be a difference that is somewhat arbitrary and hard to argue. These aren't the only views, of course, but they're the ones I've heard most.
And yes, I do think everyone will agree that this doctor is utterly revolting.