Prenatal testing: quo vadis?

 

In short, what should be tested for? Are there traits that the tests should not be used to investigate? What policy changes are needed to support ethical use of these tests?

 

With a $1.1-million grant from the National Institutes of Health, The Hastings Center is leading a foundational ethical analysis of next-generation prenatal genetic tests that will inform clinical guidelines and create a research agenda aimed at improving policy and practice. The new three-year project will be led by Josephine Johnston, director of research at The Hastings Center, and Erik Parens, senior research scholar. Co-investigators on the project are Sarah McGraw, also a research scholar at Hastings, and Hastings Center president Mildred Solomon, as well as Paul Appelbaum, a professor of psychiatry, medicine and law, and Wendy Chung, a molecular and clinical geneticist, both of Columbia University.

 

“The next generation of prenatal tests are set to offer prospective parents an enormous amount of information about the genetic make-up of their fetuses,” Johnston explains. “It is our job, through this project, to identify policies and practices that can inform, support and empower patients to make testing decisions that are consistent with their goals and values.”

 

“I personally expect significant variability in the kind of testing decisions pregnant women will want to make—including decisions about whether to be tested, what to be tested for and how to act on test results,” Johnston tells DDNews. “However, my concern is that the way these tests are currently formulated, marketed and offered to patients do not facilitate or anticipate variability in those decisions—right now women do not get much choice about what to be tested for (for instance, they can choose to decline the testing, but if they do want to be tested for, say, trisomy 13 and 18 but not 21, that is not currently a choice they get), and once tests are routinized we know from the first generation of prenatal tests and from other areas of medicine that patients often feel that they don’t have a real choice about whether to be tested (routinization can make it difficult for patients to decline testing).”

 

To consider how best to deploy these new prenatal tests The Hastings Center has recruited an international working group of experts and representatives. They include leaders of major clinical societies, clinical researchers and social scientists investigating prenatal testing, philosophers and patient representatives.

 

Until recently, prenatal genetic tests could look for a relatively small number of disorders, including Down syndrome. Combined with older technologies for securing samples of fetal DNA, advances in sequencing technology have made it possible and increasingly affordable to analyze a fetus’s entire genome. At the same time, new noninvasive prenatal tests involving a maternal blood test make it possible to gather information about the fetus’s genome ever earlier in pregnancy.

 

Although currently recommended only for women over 35, the new noninvasive tests could one day be offered to all of the four million women who give birth in the United States each year. These technologies point to a future in which prospective parents are offered a large amount of information about their fetuses, including the presence of gene variants associated with disease susceptibility, adult-onset conditions and non-disease traits.

 

“It is not yet clear whether expanded prenatal screening and testing will become routine, or what kinds of genetic markers will routinely be tested for,” Johnston states. “Right now, it does seem likely that the new noninvasive prenatal tests that analyze cell free fetal-DNA will become a routine way of screening pregnant women for chromosomal disorders, among other things, but I don’t know how many traits/markers will routinely be on those screening panels—e.g., it is not yet clear whether disease susceptibility markers (e.g., BRCA 1 and 2 genes) will be on the these tests (once it becomes possible to include them). I do think that, at least for now, these tests must be understood as screening tests and not treated as diagnostic tests—they are often more accurate than the screening modalities we had before, but they are not yet 100-percent accurate.”

 

“Next-generation prenatal tests are different in ways that are psychologically, socially and morally salient,” says Solomon. “Because the clinical and policy landscape into which these tests are entering is rapidly evolving, new research is needed to ensure their wise and effective use.”

 

Sex is usually a non-disease trait, and it is already screened or tested for during non-invasive and invasive prenatal testing, Johnston notes. “I think sex is a helpful test case for thinking about the ethics of testing for and possibly terminating pregnancies because of non-disease traits. Other non-disease traits are proving more elusive, although there are companies marketing tests for genetic markers for athleticism, and in 2009 a fertility clinic advertised that it could screen embryos for eye color, hair color and complexion. There is ongoing research to look for genetic markers associated with intelligence and sexual orientation, which we have to imagine could lead companies to seek to develop genetic tests for markers associated with those traits—they might never get there, but I think it would be imprudent not to consider this possibility.”

 

The Hastings Center is a nonpartisan research institution dedicated to bioethics and the public interest since 1969. The center is a pioneer in collaborative interdisciplinary research and dialogue on the ethical and social impact of advances in healthcare and the life sciences. The center draws on a worldwide network of experts to frame and examine issues that inform professional practice, public conversation and social policy.