I stand by what I have written, as a ‘practical matter’ what you have cited is true, but not as a dogmatic teaching of the Catholic Church:
These claims are reflective of the traditional teaching recently restated, for example, in the Instruction from the Congregation for the Doctrine of the Faith, Donum Vitae, that the “human being is to be respected and treated as a person from the moment of conception and therefore from that same moment his rights as a person must be recognized” (I, 1).
The Instruction is careful to note that the Church has not taken a philosophical position on the time of ensoulment. However, “From the moment of conception, the life of every human being is to be respected in an absolute way—” (Donum Vitae, Introduction).
While the hierarchy of the Catholic Church has left open the resolution of the actual time of ensoulment, it has in fact insisted that the prudent response would be to recognize that as a practical matter ensoulment is coincident with fertilization. This position, combined with the traditional respect-for-life position of the Church, is what propels its opposition to embryonic stem-cell research.
americancatholic.org/newsletters/CU/ac0102.asp
there is nothing more for us to discuss
in God’s peace always
micah