Colleen of Boston Brahmina explains how the alleged important question of when a fetus becomes human is not so important afterall:
If it has none until birth, abortion does not violate human rights because there are none to be violated. If it has them at the moment of conception, or at 6 months’ gestation, or when lung development suggests viability, or at any other point in utero, its mother is still its medical proxy and its rights do not extend to forcing her to use her body to maintain its life, so she may decide to abort without violating those rights.
In fact, the only potential violation of human rights is to force the pregnant woman to carry the fetus to term. She is the life-support system; she is the potential bone-marrow donor. Not even actual, born people have unconditional rights to these things. Why would a fetus?
Read the whole post. It’s quite simple, to the point and I couldn’t put it any better than her.