Fertilized but unimplanted eggs

I’m just trying to confirm something to make sure I understand it correctly – conception begins when a woman’s egg is fertilized, creating a zygote, correct? From what I’ve been reading, about of 30 percent of zygotes are rejected by the uterus before pregnancy really begins. If this is true, does this mean those zygotes are all human beings with souls who, trusting in God’s love and mercy, are in Heaven?

Or can we suppose that some level of development may need to occur before the zygote is a human being, even if we don’t know exactly how much? For example, when the sperm first touches the egg and chemical reactions start taking place, this doesn’t mean we have a zygote. At some point in development, the sperm and egg become a zygote. Do we know with certainty that the unconceived zygote is already a human being with a soul, or could it be that it becomes such a being at some perhaps unknown point?

(I understand and fully accept the Church’s teaching on contraception and abortion. I’m not asking the above as a leading question. I’m just trying to understand what the Church actually teaches about this.)

I don’t know what the church answer to this is, but my own personal feeling is that it doesn’t really count as a “person” until implantation.

Prior to that, the blastocyst still contains some cells that eventually become a person and some cells that become the placenta and the amniotic sac. Once the cells differentiate, you can tell what’s person and what’s packaging, so to speak.

That is my understanding.

I’m not so sure I would say “rejected by the uterus” so much as the embryo (which is what it is by that point) fails to implant. We don’t know why this happens. I am also unsure about the percentage of embryos that fail to implant - I hear high numbers a lot (usually it’s 50%), but it’s often presented as a justification in pro-choice circles (at least that’s where I’ve heard it - “so many babies die naturally so what’s it matter if we do it?” which is awful reasoning anyway) so I have my doubts about how true it is or about the methodology that determines the high numbers.

But even assuming that is true, yes, I believe those lost children are with God. The Church does not definitively state when ensoulment occurs, but it makes a lot of sense to me that once a human organism with its own DNA exists (the zygote), that makes it a person. Even if some of that organism develops into “packaging” as QuasiCatholic puts it, I have my own “packaging” as an adult that I lose all of the time (hair and skin cells, to name two.) It’s part of me while I have it and it serves a purpose, but once it’s detached it’s no longer mine.


From the Catechism:

2270 Human life must be respected and protected absolutely from the moment of conception.

We don’t know precisely. And it doesn’t matter precisely. We do know that we respect and protect all human life from the moment of conception. That is the moment the egg and sperm unite.

The Church doesn’t teach anything definitely because it is not know and God has not revealed it in such scientific terms. We know a human being exists from the moment of conception. God gives each human being a soul. Therefore, we can only deduce God gives the soul at the moment of a new human being comes into existence (conception) and operate accordingly.

It’s simple…

*Fertilized but unimplanted eggs *are people.

OK, new question: God does everything for a reason, right? What reason do you think he would have for creating millions of little souls who then go right back to him without anyone ever even knowing they existed? Seems like an odd thing to do :shrug:

In our fallen world, we all die a physical death. Defects of genetics and malfunctions of the reproductive process are consequences of the fallen world.

It matters not if we die 1 minute or 100 years after our conception, God knows and loves us just the same.

They do not exist without “anyone” knowing they existed. God knows they existed. They *continue *to exist for all eternity.

Thanks for the answers.

How do we even know what if any percentage of fertilized eggs fail to implant? How does one know that without examining the menstrual discharge of every woman every month looking for non-implanted zygotes?

From what I read about it, it sounds like basically, yes, scientists put together what they deemed a representative sample and analyzed their discharge on an ongoing basis. I’m only assuming they knew what they were doing.

Here is a USCF Medical Center page making the 50 percent claim, although it doesn’t go into how that number was arrived at:

In nature, 50 percent of all fertilized eggs are lost before a woman’s missed menses. In the in vitro fertilization (IVF) process as well, an embryo may begin to develop but not make it to the blastocyst stage — the first stage where those cells destined to become the fetus separate from those that will become the placenta. The blastocyst may implant but not grow, or the blastocyst may grow but stop developing before the two week time at which a pregnancy can be detected. The receptivity of the uterus and the health of the embryo are important for the implantation process.

This really has no bearing on what Catholics ought to do regarding conception and pregnancy, since contraception is immoral at any stage whether a baby has been conceived or not.

I’ve found some pages arguing that we shouldn’t be opposed to various actions that lead to the destruction of embryos because most of those embryos would have died naturally anyway. That argument is pretty lame – everyone will die at some point; that doesn’t give us the right to take innocent lives with our own hands.

I saw an article headlined “Is Heaven Populated Chiefly by the Souls of Embryos?,” which I thought was kind of an interesting theological question, but not really what the article was about. The headline was just a flippant introduction to the kind of argument I mention above.

Another article argues that, if we really consider all fertilized eggs to be human beings, we ought to be in favor of legalized, widespread use of birth-control pills that, statistically speaking, would (according to the article) reduce the number of zygotes that would be created in the first place and therefore die.

This argument is interesting, and I have to admit it took me a while to recognize a few major problems with the author’s reasoning:

  1. She ignores the moral distinction between natural death and the deliberate taking of innocent human life.

To be fair, the author is unconvinced that birth-control pills actually acts as abortifacients. She accepts the premise only for the sake of argument. Still, her rebuttal is that if the number of deaths resulting from taking of a pill (a deliberate act) is less than those that would have died naturally, than taking the pill is to be commended.

  1. She assumes that it is better for a human being not to exist than to be created and die in the womb.

We don’t know what God’s plan is for unborn children who die naturally in the womb. For all we know, in His divine justice and mercy, He brings those children straight to Heaven, where they are made perfect by Christ and offer prayers for those on earth and in purgatory, with prayers that are especially pure because these children never knew sin. Or, maybe God has another plan, but we know that God is good and so are His plans.

If one reasons that it is better never to exist than to die early, the question I would have to ask would be, how early? How much earthly life must one be given before their existence will have been a good thing? Human life, regardless of how long it persists, is sacred.

  1. She assumes that contraception itself is a morally acceptable means of preventing pregnancy even if it caused no lives to be lost.

She is of course not alone in or culture in making this assumption. Too many in our society lack proper respect for the marital act. Even many of those who oppose abortion see no problem with contraception, so long as that contraception cannot act as an abortifacient.

Answering “why” is immaterial when we get into whether or not something is true.

Nevertheless, one reasons for any suffering is to allow a higher love to enter the world. It takes a tremendous amount of love for God and creation to fight for the lives even of those in the most nascent stage that we normatively can’t physically see.

Thank you for the detailed response. Yes, I have seen such articles as you have referenced as well, including articles in medical journals, which all seem to assume the accuracy of the 50% figure. But I have yet to see anyone lay out in detail the experimental methods that gave them such certainty about that figure, or why the particular studies, which are hardly ever referenced, can be extrapolated to the entire population.

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