I think this whole issue illustrates one of the theological/philosophical problems with conflating “life begins at conception” with the idea that a fertilized egg is a human being with a human soul. I agree life begins at conception, but I’m not at all sold on the idea that a fertilized egg is a human with a human soul and human rights. It’s a potential human. If you combine the contention that all fertilized eggs are ensouled humans and children who die before an age of accountability go to heaven, then heaven will be filled with mostly people who never had anything close to a human life, people who were never even conscious in any sense of the word. That seems pretty untenable to me. I am skeptical of the idea that at fertilization, cells are miraculously zapped with a soul. I think “soul” is a construct we use to describe the spiritual dimension of humanity, but we are holistic beings and I don’t think you can divorce it from our embodied existence/biology. How does something without a mind have a soul?
I guess I have never thought of eggs not implanting as a natural evil. I know people who have struggled with infertility, but the “evil” of the situation is more wrapped up in the disappointment and unfulfilled hopes and dreams of the adult humans involved, not in the fact that fertilized eggs are somehow mercilessly killed by fate or nature or whatever.
Death is part of healthy life. The fact that not all fertilized eggs implant was part of healthy human reproduction for millennia before artificial birth control. It kept women from becoming pregnant when they were undernourished or living in stressful conditions. It kept population sizes in a community sustainable. It’s all part of the abundance of nature. There is plenty of room for “failure.” If every acorn grew into a tree, we’d have problems.