How often human conception fails: Thoughts on ensoulment and more

So, what happens to that soul that supposedly is formed at conception if conception has a 50 percent failure rate?

First, yes you read that right. Conception has a 50 percent failure rate of actually producing a living baby, if not more than that.

First, about one-quarter of fertilized eggs fail to implant in the uterine wall. So, we’re down to 75 percent. Of that number, about one-third are spontaneously aborted, usually due to great genetic abnormalities, in the first six weeks after conception. (Many women will miss a period, think maybe they’re pregnant, then have what seems to be a late period with heavy bleeding. It’s not a period; it’s a spontaneous abortion.) That takes us down to 50 percent. Throw in later-pregnancy miscarriages, and we’re below that mark.

But, if we follow the line of good conservative Catholics, evangelicals, Mormons, etc. (but not Orthodox Jews — if you read the Torah on pregnancy and from it argue to soul implantation, boys are soulless until the 40th day of a pregnancy and girls until the 80th day), God is putting souls in a lot of embryos that never make it to the fetus stage of development, let alone birth. Sounds like a pretty spendthrift, let alone cruel and capricious, deity to me.

What if we posit a divinity that ensouls a human body at the moment of birth? I counter, what if that baby dies a day later? Or a minute? You’ve again got a Numero Uno wildly and extravagantly scattering soul-seed like ryegrass for fall grass cover. It’s kind of like the illogic of Aristotle’s Prime Mover argument with reverse temporality direction. And, you so-called “liberal Christians” and others, where does your version of ensoulment in particular, and metaphysical dualism in general, square with this?

And, I haven't even covered idential twins here, or chimeras.

Now, Orthodox Jews are largely exempt, right?

Well, no ... because in VERY rare cases, you can have identical twins of different sexes, which makes Yahweh really look weird in playing ensoulment favorites. And? What what if that male embryo in such cases dies in days 41-79 but the female survives to term? More capriciousness.

Nor have we noted this isn't just a monotheist's problem.

Now, many Buddhists believe, or say they believe, only in the reincarnation of a life force, but Hindus and New Agers believe in a soul that's reincarnated. I have never tried to pin down a slippery New Ager, but, from what I know of Hinduism, I'm guessing they believe this happens with conception. So, when identical twins form, which gets "the" reincarnated soul?

Update, May 2, 2021: Fascinating Smithsonian piece here. If you're familiar with what chimeras are, namely a human fetus that has absorbed another in the womb, the discovery that moms can become chimeras from their fetuses is ... fascinating.