A By Dr. Jeffrey Kahn

new type of embryo testing is being offered by a growing number of fertility clinics as a way of improving the chances of a successful pregnancy. It involves genetic testing of chromosomes in embryos created by in vitro fertilization and implanting only those embryos with normal chromosomes into the mother.

The logic is that even if embryos appear normal in the lab, subtle chromosomal abnormalities can prevent a pregnancy from continuing past a certain point. Screening embryos before implantation is a way to avoid this problem.

While such screening seems to improve the odds of having a baby, it also raises ethical and policy issues. The testing process also identifies the gender of the embryo, which might or might not be made available to the couple to help them decide which embryos to implant.

And while the testing is being initially offered to help couples overcome infertility, it also affords the chance to perform other genetic tests on the embryo. Is such embryo screening a good thing? And which tests should be added as they become available?

There has been much discussion about the appropriate uses of genetic testing in embryos. Sparking debate have been stories about couples trying to “create” a genetically matched cord blood donor for their sick child and a woman screening embryos to make sure her offspring would not be afflicted with the same genetic form of early-onset Alzheimer’s disease that she had.

These two cases were seen as controversial uses of technology. Current screening efforts are different in that they propose testing only for what will give the embryo a better chance at birth. This laudable goal will allow regular genetic testing using IVF and effectively spread acceptance of genetic testing on embryos.

But why should we stop at screening embryos only to increase their chances of birth? As we learn more about our genetic makeup, and genetic testing becomes more sophisticated, there will be both the opportunity and the desire to select more characteristics of future children.

Why not screen for diseases or increased risk of illness in the future? Why not test for gender, and eventually physical and behavioral traits? The problem is that we have no mechanism to make decisions when to stop.

There is little, if any, oversight of in vitro fertilization for several reasons:

ïThe U.S. federal government hasn’t funded research on embryos as a matter of policy dating to the mid-1980s, and so has avoided making rules about such research in the private sector.

ïHealth insurance companies generally don’t pay for in vitro fertilization and embryo testing, so no criteria have been established to receive approval from payers, which means we’re left with “whatever the market will bear.”

ïSince reproductive medicine is such a market-driven part of medicine, clinics compete to offer the latest services and have difficulty regulating themselves.

It is time to take a hard look at oversight in both the making and testing of embryos. We’ve come to realize that in virtro fertilization and embryo testing technologies are closely linked with stem cell research, since embryos for embryonic stem cell research come from these technologies and the clinics where these technologies are practiced. It is becoming increasingly likely that the government will step in and fill the policy void, either through an existing regulatory mechanism such as the Food and Drug Administration or by Congress passing legislation.

Before that happens, these big decisions deserve societal discussion and debate in which we ask ourselves not whether we can choose what our children will be like, but whether we should.