I am not able to understand your reasoning on the act of abortion being a right under the first amendment.
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
??

Thor, you still insist the only pro-life argument is religious. You and I have been down that road and I have clearly explained my pro-life position is NOT religious nor does it need to be, leaving your religion argument irrelevant. True, the most vociferous pro-life advocates are a religious people who use their religion as a chief argument, but that is irrelevant as well.

Here's an overview reiteration of my position as follows so others reading this have an understanding of what it is:

Are we a civilized people? I say we are or, at least try to be, and a defining characteristic of a civilized people is respect for the life and value of each human individual within the civilization and that value is (or should be) protected by the laws of the society claiming to be civilized. This is very objectivist, I might add.

So, what is this individual? This living human that has value within a civilized environment? Biologically (scientifically if you will) it is a living organism that transitions through various phases from its beginning at conception. A normal life cycle of our species includes a gestation phase, childhood phase, adolescent phase, adult phase, and finally a geriatric phase (if I left any out please feel free to fill in). I argue to be civilized the gestation phase deserves the same protections as any of the other phases.

I've seen plenty of arguments, including from Ayn Rand, that the gestation phase is fair game to willy-nilly kill off a human being and such killing has taken place by the millions within our so-called civilization. The criteria defending such practice is normally some pulled-out-of-the-ass fetus or cellular characteristic that has to be met to finally admit it's a human life. IMHO, the ONLY way to be sure of its humanity is at conception.

A few thoughts at large:

Pregnancy is a normal and natural condition of the female members of our species who are sexually active. Redefining natural pregnancy as a rights violation of the mother or redefining a fetus (human in gestation phase) as a parasite and therefore deserves a death sentence on a whim is patently absurd, at least if you want to claim yourself civilized.

There can be exceptions, such as self preservation of the mother, but these are serious decisions not to be made "willy-nilly".

The cancer cell argument is irrelevant as, even though they contain human DNA, they will never pass through the life phases of our species. Even if they could they would fall into the self preservation exception of the person carrying them. Yes, you can kill cancer cells with human DNA and still be civilized.