The adoption of embryos produced for in vitro fertilization (IVF) by US Christian groups who claim they are thereby saving lives is yet another example of the triumph of religious dogma over science. The movement, which has received support from US President George W. Bush, not only muddies the debate over stem-cell research but is fundamentally insulting, and potentially damaging, to couples who hope to use IVF to overcome infertility.

At the centre of this issue is the Snowflakes Program, which has received support and funding from the US government. Snowflakes allows couples to 'adopt' embryos that are made available by US fertility clinics.

Some couples who have IVF treatment produce a few surplus embryos that are not implanted into the woman's womb. These may, if they are of sufficient quality, be frozen and stored for subsequent use, either by the same couple or, if the couple agrees, by others.

Not all of the left-over embryos from IVF are viable. Credit: © Punchstock

Snowflake participants are not necessarily infertile, however. They opt to have such embryos implanted simply to save the embryos from being discarded (killed, as they put it) or, if local laws allow it, used for stem-cell research. Dozens of babies have been born this way since Snowflakes began in 1997.

These children are probably born into loving families, which is wonderful. But the rhetoric behind the process is certainly not.

No such thing as a spare embryo

The term 'embryo adoption' implies that all IVF embryos are children waiting to be given the chance (as Snowflakes puts it) to "realize their ultimate purpose - life". As far as the organization is concerned, each embryo is already a human life, not a product to be thrown away if not needed.

That message is embraced by President Bush. At a protest by Snowflakes participants against a bill for embryonic stem-cell research passed by the US House of Representatives last month, he said, "There is no such thing as a spare embryo. Every embryo is unique and genetically complete like every other human being."

The experience of IVF indicates otherwise. Most embryos produced this way are not frozen at all, because the clusters of typically 4-8 cells do not divide fast or cleanly enough to ever have any real chance of developing. For whatever reason, these embryos do not have what it takes to develop into a human being.

That's normal even in fertile women. It is estimated that more than 50% of fertilized eggs terminate at so early a stage that conception isn't even noticed. Even when the best embryos are selected for IVF implantation, the success rate for a full-term pregnancy is only around 25%, as participants in Snowflakes programmes discover.

Moral minefield

To suggest, as these groups do, that IVF couples casually throw away 'unwanted' embryos is to show no understanding of the difficult decisions such couples face and the care and agonizing that goes into making them. Likewise, to suggest that IVF procedures should create only as many embryos as are going to be implanted, is to assert that the success rate for IVF should be reduced from its current harsh margin of about one in four to a fraction of that.

At root, the attitude represented by Snowflakes illustrates the problem of reconciling a centuries-old biblical view of life with modern biological understanding. While the processes of conception and embryonic growth remained obscure, it was natural to regard the creation of a human being as a mysterious event that took place in a miraculous instant. Now we know that it is a gradual and rather precarious process that fails more often than it succeeds.

Perhaps, all things considered, organizations like Snowflakes should be more concerned about the plight of the millions of orphaned children around the globe than the destiny of frozen cells.