Testing for medical purposes brings its own set of problems. Only a limited number of genetic variations present the kind of clear-cut case for which PGD was originally developed: the certainty of a serious or fatal disease. But what about testing for genes that merely raise the risk of a disease? Or for genes linked to a relatively manageable disease, such as diabetes? How serious must a disease be to justify the costly and potentially risky process of IVF?
“That is a major debate in the profession,” says George Annas, chair of the department of health law, bioethics, and human rights at the Boston University School of Public Health. Another problem is that parents may eventually find themselves with more information than they or their doctors know how to use. As more disease-linked gene variants are discovered–and the list is rapidly growing–parents will face so many choices that it will be difficult, if not impossible, to determine which genetic combination will produce the healthiest child.
In the United Kingdom, a government body licenses fertility labs and regulates which tests can be administered. But the United States has fewer rules; it is one of the few countries, for example, that permit nonmedical sex selection. “Today, in this country, the clinics are the gatekeepers,” says Vardit Ravitsky, a bioethicist at the University of Pennsylvania. “If you have cash and can find a clinic to provide the service, you can get it, whether it’s a test for Huntington’s disease or sex selection.”
So decisions regarding PGD are left in the hands of doctors or clinics. Professional societies provide some ethical guidelines–the American Society for Reproductive Medicine, for example, recommends against sex selection for nonmedical reasons, though it has little to say about other aspects of PGD. But voluntary guidelines regulating a profit-driven industry may not be enough to help prospective parents. “I think there will be people hyping the advantages of this, which will be just like pharmaceutical advertising today,” says Caplan. “I think people will be guilted into doing this, rather than choosing it.” They may also be “guilted” into testing that doesn’t make good on the promise of a healthier child; most of the newly discovered genes have relatively weak correlations with disease or play small roles in complicated processes, and some may affect the body in ways that scientists don’t yet fully understand.
Some kind of regulation for preimplantation genetic testing is needed, but the rules must focus not on limiting which tests a parent can choose but on making sure that clinics can scientifically justify the claims made for each test. Then parents and their doctors can begin to make informed choices. “I definitely think the government has a role to play in regulating the safety and quality of tests and in the application of tests,” says Adamson. “But the final choice, once tests are considered to be scientifically legitimate, should be left up to patients and physicians.”