Parasite is often applied, as you are doing here, as rationale to kill that to which the term is applied.
You can debate within yourself all you like as to whether the word parasite applies to the scientifically determined newly conceived person.
But if you use that specious application to justify murdering that scientifically determined person, you will still be murdering a person, and, you will know it.
Your heart won't let you live in peace without convicting you of your sophistry.
Next thing you know you'll idiosyncratically apply the word "parasite" to the new-born child suckling on her mother's breast. 
The parasite defense was long-ago defeated postnatally as unjustified reason for murder.
It is just as inapplicable prenatally.
Once a human being exists, no matter where that human being exists, attempts to apply sophistries such as the parasite defense in no way degrades the reality of the existence of the newly conceived person, and thus in no way justifies murdering that person.
The parasite defense simply holds no water among intelligent, rational people who respect the truth and reality more than utilitarian coping excuses.
And, of course, fails as rational grounds for murdering that child.
You may not like the unique reality of women with regard to gestation.
But you can't go advocating murder simply because you don't like it.
No one's mere "change of mind" outside of a legitimate life-or-death battle is ever moral justification for such killing.
Your statement was that it is okay to, in scientific effect, murder someone who cannot live outside of their natural element.
I merely pointed out to you that you can't live outside of your natural element either, as the hospitable surface of Earth is your natural element, and if you suddenly found yourself in outer space, you couldn't breath and you'd die, but the fact of it is not grounds for murdering you.
Neither is the fact that the newly conceived person cannot live outside of that person's natural element, the womb, grounds for murdering that person.
Thus the fact that the newly conceived person cannot live outside of that person's natural element is irrelevant with regard to your sophistry of rationalizing that it is therefore okay to murder that person.
It really is that simple, Mare.
Your statement is erroneous.
Definitive propriety was shown to be foundational.
If you don't believe so, then in violation of definitive propriety you are free to drink some hemlock and call it coffee if you wish ... but I certainly would advise against it.
Maybe to your utilitarian moral relativistic perspective, but not to those who value the truth of reality.
Definitive propriety means that terms apply appropriately with respect to accurate definition.
You can call a woman a "dog" if you wish ... but despite your inablilty to find her attractive, if you attempt to violate accurate application of definitive propriety and attach a leash to her for some walkies, you may quickly find out that definitive propriety most certainly does not mean whatever people want it to mean.
Intelligent rational people accurately apply definitive propriety congruent with the reality of the situation at hand.
If you want to work and play well with others, you need to respect definitive propriety.
Again, you are in error in two ways.
First, that the statement needs to be part of the scientific method to be justified in context (it doesn't).
And second in that scientists in association with their profession don't make these statements (social scientists, sociologists, most certainly do).
I realize you are troubled by the accurate presentation of science in the opening post, troubled by the future implications of the scientific reality that a person begins to live at conception, but attempting to demean air-tight scientific reality is futile.
Better is to face the truth of what it means and make changes in behavior accordingly ... at least if one wishes to appear moral, intelligent, and rational.
Erroneous ... in that there's nothing religious about the opening post.
Immaterial ... in that there is no rational conjecture about the high school science textbook level material presented in the opening post that is an obvious reality.
Mare, simply face it -- you are feeling controlled by the understandable implications of the accurate scientific presentation of the opening post, and you don't like feeling controlled.
That's your entire motivation for your post.
