Zeev...
Both arguments are made by the pro-life movement and if they are correct that "life (ensoulment) begins at conception" is correct, I would agree with them in both arguments. Of course that still does not solve the question of what to do when a choice has to be made between the life of the mother or that of the unborn. Fortunately, that is a relatively rare occurrence, but I would tend to favor saving the mother.
The entire question for me is "when does the fetus become a person" which would be the time that God ensouled it (in my thinking, anyway.) The pro-life movement argues that it always occurs at conception, but I find the scriptural evidence for that to be inconclusive even though a lot of people who I respect very much (and who have spent for more of their lives studying the Bible than I) agree with that position. Because I am unsure, I prefer the more conservative idea of being against all abortions except to save the life of the mother.
mlsoft