US Official Urges Americans To Reconsider Privacy
A fetus has value, but not the value of a living person.
An embryonic stem cell, or the initial fertilized 'egg' is an undifferentiated mass of stem cells, that can develop into any part of the human body, but it is not a person.
It has the potential to become a person, but it also has the potential to just form say, a toenail.
It can be divided into two, three or more to produce identical twins, triplets, or even more people - at what point is this one or more people?
Even more interestingly - rarely, two separate eggs or masses of embryonic stem cells can fuse in the womb to form a single person, with two different genetic lines, even of different sexes (even less common, but causing some varieties of hermaphoditism). This is known as mosaicism, or sometimes even referred to human chimeras.
Neither embryo 'died', and yet a mosaic person is not 'two' people, but one. Therefore, embryos are not people.
So, if we know embryos are not people, and are not people for awhile, and yet babies are - then, they become people as they develop at some point between these two points, and we're back to arguing exactly when.
For comparison, Judaic thought holds an embryo to be as 'mere water' for the first 40 days, and after that, of value but still essentially part of the mother (of her thigh) and not-a-person until birth (when the head, or most of the body has exited).
From a biological standpoint, over 50% of fertilized eggs are lost or rejected before the end of the first trimester, most in the first month or so. After that, you have the earliest point at which a fetus begins to be viable (ie, low survival rate, and likely to have disabilities), where the existing life (mother) should take priority, through to the likelihood of the birth of a healthy infant, and so similar priority.
All in all, even better would be more of a priority on efficient methods to prevent conception in the first place. Both making them available, and developing new ones. There's got to be a better way. The current ones, while probably the greatest social breakthrough of the last 100 years, do kind of suck. :P