Start with this consequence of the essentiality of origins:
- The identity of an individual depends on the exact time of her coming-into-existence.
- There is no true probabilistic counterfactual of the form: "If we were to do A, then an individual would be not unlikely to come into existence exactly at t."
- People cannot procreate out of love for the particular individual who would likely come into existence from the procreation.
Now, notice that God in creating an individual--either ex nihilo or in cooperating with the joining of an egg and sperm--is under no such constraints. Thus it is possible for God to act in such a way that were he to act so, an individual would come into existence at a precise time. And the same is true for other features of the origination of the individual besides the time of its occurrence. So God could create out of love for the particular individual who would come into existence from the creation.
This fact suggests a weakness in premise (2) of my above argument. It could be that God has already decided what individual would result if a couple chose to procreate, and has resolved in particular that sperm and egg would meet at a particular time, as long as the couple chooses the procreate. God, thus, is resolved to control all the quantum phenomena to ensure a particular circumstance of origination. Thus it's up to the couple whether someone comes into existence, but there is a particular someone who would exist if the couple procreated. It would not be surprising if this were to happen in special cases, and it would be possible for it to happen in all cases. I don't know if it does, though.
The upshot of the above argument, thus, is that unless special theological assumptions hold, it is not possible for a couple to decide whether to procreate out of love for the particular child that would result.