God so opposes IVF that a new human life is allowed to be created by this method anyway?
James, may I suggest that you reread the article I posted. The most “viable” embryos are allowed to live. All the others are killed/allowed to die. Not to mention that, in the Catholic Church, masturbation(used for collection of the sperm employed in fertilization of ovum) is a mortal sin, one against both natural law and divine law.
Suppose, for the sake of discussion, that a hypothetical couple were trying to use IVF. While 30 ovum were collected and fertilized, only one was allowed to grow, in utero. That math means 29 babies are killed/allowed to die. Also, there are those who use IVF and then selectively abort (murder) babies not of the preferred gender, whatever that may be.
Another Church teaching, simplified, is that the ends do not justify the means. Evil actions cannot, ever, make for good happening. So while a human life is precious, as a baby most certainly is, the murder of up to ~30 other babies-to-have-been is never acceptable.
Yes, very many children are conceived under circumstances that fall far short of love and marriage. Babies do get conceived by acts of random haphazard screwing, commercial breeding contracts (e.g. surrogacy), laboratory production processes, assault-rape, prostitution, and so forth. That doesn't make the baby's life worth less, or make the baby an unworthy person; but his parents have brought him into existence in an unworthy way.
In other words, it fell short of what any child would want for himself and what God wants for him: that he should have been brought into existence by the bodily and loving union of his parents.
(That's why marital sexual union is such a beautiful and fitting way. It is a kind of micro-cosmos, bringing together male and female, soul and body, spiritual and physical, love and life: a child in the center of a little paradise, a little world made by his father and mother's love. That's something inherently fascinating, intricate, brilliantly designed, and beautiful. It should be considered every child's birthright.)
The problem with IVF (aside from killing the leftover embryos) is that it makes the conception of a baby into a lab project and a commercial transaction: it's objectively dehumanizing. It pushes him into the category of a product rather than a person.
A case here in Tennessee illustrated how crass it can be. A divorcing husband and wife sued each other over the ownership of their own cryopreserved, embryonic children. The State appeals court ruled that it was not a matter of "custody", just a matter of lawful disposal. They were like a can of old paint back in the garage. They could be discarded as the parents --- no, the "owners" -- saw fit.