written by Christopher Register
Evangelicals and other pro-life advocates have underappreciated reasons to support in vitro fertilization (IVF) and funding for maternal health and reproductive technologies in general.
These reasons stem from the surprisingly high rate of natural miscarriage. I suggest that advances in IVF technology may ultimately lead to fewer total embryos being miscarried or discarded than could be achieved without IVF. This fact should appeal to evangelicals or others who believe that a fertilized ovum has considerable intrinsic moral value.
Since the judicial overturn of Roe v. Wade in June of 2022, opposition to IVF in the U.S. has grown. Just last month, a prominent group of U.S. evangelicals, the Southern Baptist Convention, voted to condemn IVF, even advocating that the government ban the procedure. The central argument of this blog post is that they may be making a mistake, even on their own terms.
Embryo loss through IVF and miscarriage
To review the basics of IVF, it involves a human egg being fertilized outside the body. Over the next few days, the egg develops and divides until—having become a group of cells similar to the embryo depicted above—it is either frozen or implanted into someone’s uterus to continue gestating. Typically, the procedure produces about 5-10 embryos in total in case some are not viable, where the frozen embryos that go unused will ultimately be discarded.
For many evangelicals and other pro-life advocates, the main argument against IVF is the same or substantively similar to the argument traditionally levied against abortion: a fertilized human egg is a human being, a human person, or the morally weighty start of a human “life”, and therefore has the same or similar rights and worth as the rest of us.
Noting that IVF usually involves “discarding” the unused embryos, which then die, those who argue against IVF often assert that it is wrong to destroy or neglect human life, and that it is therefore wrong to create an embryo only later to discard it. For example, speaking in favor of the SBC resolution to condemn IVF, Monica Hall asks, “Most embryos created through IVF die at some point in the process. How could it be considered ethical to create human life knowing death is a probability?” Her answer is that it cannot.
It is understandable that, for people convinced of the value of even early human embryos, the discarding or destruction of such embryos as a part of the IVF process may be genuinely concerning. But, even accepting that concern, there is a surprising but largely unknown fact about human gestation that complicates the picture considerably: that there are many, many unnoticed miscarriages of pregnancy, resulting in the loss or “death” of a fertilized human egg.
Scientists and health professionals estimate that 20% to 80% of all pregnancies end in miscarriage, and the figure is often put at about 50% (for example, here). So, in the natural course of gestation, about half of all fertilized eggs do not survive. So, for every person you know, there was an embryo that was miscarried. As a consequence, if one accepts that a fertilized egg is a “human life” in some meaningful sense, miscarriage ends as many human lives as every other cause of death combined.*
How does this fact complicate the ethics of IVF? To begin, it shows that natural conception is disastrous for human embryos. If a high probability of premature death makes IVF ethically troublesome, then it can make attempts at natural conception problematic too. This is because there is no currently available mechanism for creating and gestating an embryo that doesn’t involve a rather high probability of premature death. If the probability argument–that it’s wrong to knowingly act in ways that have a good chance of bringing an embryo into existence that will soon die–were correct, then it might effectively require anti-natalism, roughly, the view that it is morally wrong to try to conceive and bear children.
Needless to say, such a controversial view is likely not one that pro-life conservatives would seriously entertain, much less accept. So let us put the prohibition from the ‘probability of (premature) death’ against embryo creation aside: perhaps the continuation of humanity is worth repeatedly putting embryos in perilous situations.
Still, the absence of a safe mechanism for creating human life doesn’t mean that a safe mechanism is impossible. And even if a completely safe mechanism is impossible, there may still be reason to pursue safer mechanisms—mechanisms of creating human life that reduce the probability of embryo death. Is a safer mechanism possible? I suspect that safer mechanisms will involve current or future IVF technology, along with improving maternal health in general.
How could IVF be safer than natural conception?
To be safer than natural conception, IVF must reduce net embryo loss. With current technology and practices, IVF almost always results in the loss of multiple embryos, and so it’s likely only a safer mechanism for a subset of the population—individuals who are likely to conceive more than about 5-10 times for each successful gestation. Given that many people try for years without a successful pregnancy, however, it’s not implausible that, even at the current level of technology, IVF is in some cases safer for embryos than technologically unassisted conception. (My own parents tried for about 4 years for me and then about 4 years for my sister.)
Unfortunately, data about rates of embryo loss per attempt at conception is hard to come by, so it’s difficult to estimate how often IVF is safer. Another practical problem is that it’s difficult to identify the relevant cases in advance. Even so, it’s plausible that, if IVF were prohibited and couples were forced to continuing trying to conceive without the aid of reproductive technology, many people would lose more embryos than if IVF had been available to them.
If IVF technology can be improved in the future, the net benefits of IVF may be higher, expanding the proportion of cases in which it’s the safest available option. With increased funding for research into IVF and maternal health, more advanced IVF technology create fewer embryos, thereby ultimately reducing the loss of human embryos in the process. Just how this might work is complicated, as it depends on many factors to do with the genetics of sperm and egg, the health of human gametes, maternal health, and the process of IVF. As an example, I’ll consider just one factor and the potential net benefit that future IVF may provide over natural conception.
One way to reduce the number of embryo deaths in IVF involves chromosomal screening. Some estimates suggest that about 50% of natural embryo deaths stem from chromosomal abnormalities known as aneuploidies (having a number of chromosomes that isn’t 46). That amounts to roughly 75 million embryo deaths per year. For comparison, the next highest cause of death worldwide is heart disease, which killed about 30 million people in 2019. If aneuploidies could be addressed during IVF, then IVF could prevent many of these embryonic deaths.
To spell the argument out, then: at present a high proportion of embryo loss in IVF is likely due to aneuploidies, with a high proportion of aneuploidic embryos having an aneuploidy of meiotic origin (that is, at least one gamete did not have 23 chromosomes). The creation of these embryos could in principle be prevented by chromosomal screening prior to fertilization. If aneuploidies in IVF could be significantly reduced, then embryo loss during IVF could be reduced and (potentially) millions of embryo deaths could be prevented. This is simply not possible through natural conception. Thus, if non-aneuploidic (euploidic) embryo loss in IVF could be reduced to, say, 1 embryo per 3 successful gestations, then IVF would be safer than natural reproduction in general.
That is, of course, a very tall order, as it would require other significant reductions in embryo loss during IVF. But with enough investment in IVF research and technology, it may well be achievable. And according to the argument I am making here, this is something that pro-life advocates should therefore welcome and support, rather than oppose, as many currently claim to do.
Other strategies for reducing embryo death may involve other kinds of genetic screening of gametes, improvements to paternal and maternal health, and the development of treatments to facilitate healthy gestation. All that is to say: for those who profess concern about the longevity and eventual welfare of human embryos, there are serious reasons to support investment in reproductive health research and technologies, including IVF, and to avoid prohibiting IVF for those who need it the most.
Other considerations
So far, my discussion has focused on reasons that flow from concern for embryos, while I’ve ignored some other considerations. Most significant among these is the objection that while natural gestation only involves the unintended death (i.e., cessation of development) of embryos, IVF involves deliberately bringing embryos that will die into existence.
However, it’s not clear how morally significant the difference between the cases really is. With IVF, the loss of embryos is not intended, even if it’s foreseen. Just as with the perils of natural gestation, the loss of embryos during IVF is an unintended side-effect of an intention to bring a child into existence.
A second objection is that, unlike with natural gestation, we know that embryos will be lost during IVF. Yet, on further inspection, this difference also turns out to be subtle. Even if we don’t know that there will be embryo loss for each and every conception, we do know know that embryos will be lost during natural gestation considered in the aggregate and that it’s not unlikely for any given conception.
Ultimately, the moral weight of these subtle issues must ultimately be compared to the value of embryo loss—a value that I think many pro-life advocates feel is paramount.
Thanks to Nathan Nobis for helpful comments on this post.
*See Ord 2008 and Berg 2017 for arguments about how pro-life advocates should respond to the high rate of natural miscarriage; see Miller 2023 for a critical discussion of those arguments that nevertheless agrees with my numbers. Ord 2008 and Berg 2017 argue roughly that if early embryos matter in the way that developed human people matter, then we should do a great deal to prevent miscarriages such as by investing billions of dollars in research and health technology development. Against this conclusion, Colgrove 2021 argues that because miscarriages have a variety of causes and are therefore hard to prevent, the demand to prevent them is not especially strong. Colgrove’s argument does not address the feasibility of preventing embryo death via IVF.
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