Most spiritual people believe an embryo becomes a "person" when the soul enters the fetus.  As of yet, no one has been able to determine when that is.  All the research I've done indicates that it varies from pregnancy to pregnancy.

Correspondingly, death comes when the soul leaves the body, and, again, this moment varies.

It's all about the soul, my friends, not the body, which is the mere receptacle of the soul for a short period of time.  We must consider, too, that a particular fetus, whether damaged or perfect, came into that woman's womb for a reason.