Abortion and the argument of implantation

I've heard pro-abortionists argue that the embryo is not a person until it implants itself on uterus.  The argument generally goes like this: the process from conception to implantation on the wall of the uterus takes several days.  Beyond that, some 20-50% of embryos miscarry prior to implantation.  Once the embryo does implant, it sends out hormones to “signal” its attachment which also ceases the mother’s menstrual cycle.  Therefore, it is ridiculous to think that every embryo is a person.  Therefore, the embryo is not a person.

In response to this decisive moment being the moment when personhood is achieved, we can say a couple of things.  First, if it were universally agreed upon that personhood begins at implantation, then there would hardly be any abortions except for the spontaneous kind, which are also known as miscarriages.  However, personhood is not dependent on other people (in this case, the mother’s body) being aware of it by the hormone signal it produces.   Most people in the world are not aware that I exist; am I therefore not a person?

Second, the essence of the nature of the embryo is not dependent on how many of its kind survive.  Just because a large number of pre-implantation embryos do not survive does not change what it is in its essence.  Those that do miscarry die natural deaths are not being aborted in the same way as is what’s being debated in our country these days.  By the way, 100% of all people die.

Are you really saying that the potentially millions of frozen embryos are real people, just like you and me, with rights?  If so, why aren't you trying to save them?

Yes, I'm saying that.  It doesn't matter how incredulous you feel about the logic of it; what matters is whether the embryo is a person, and in every way that matters (i.e., the embryo is genetically distinct and alive) it is.  This is why I'm against embryonic stem cell research and am alarmed at the cavalier way fertilization treatments make dozens of embryos without ever intending to implant them all.  A pro-life couple can use IVF if they're willing to eventually implant all the embryos made for them (not necessarily all at once) and at least give them the same chance at development as a naturally-conceived embryo.

And in the way in which I'm capable, I am trying to save them by trying to change people's minds about what embryos are: very small, undeveloped human beings, but human beings nonetheless.

The argument of implantation fails to be valid because it defines one's essence by other people's awareness of its existence, and it arbitrarily assigns personhood to whether most of its kind survive.