Tag Archives: prenatal whole exome sequencing

Are We Ready For This?

Recent advances in genetic testing technology have us poised on the brink of a new paradigm of prenatal diagnosis – prenatal screening for all genetic and chromosomal conditions. Okay, not all disorders, but lots. Non-invasive Prenatal Testing (NIPT), whole exome sequencing, and expanded carrier screening are close to being available and affordable to a large proportion of the population. This is the culmination of a trend that began with the introduction of amniocentesis in the late 1960s, followed by ultrasonography, maternal serum screening, microarrays, and cell free placental DNA in maternal serum. From a strictly technical standpoint, each technology, while far from perfect, was an improvement on its predecessors in terms of accuracy, detection, false positive rates, and the range of  detectable genetic conditions.

On the surface, this sounds like progress, and it is, in many ways. These technologies can contribute to the reduction of the incidence genetic conditions, some of which are pretty serious, a long-standing goal of medical genetics since its inception, as Nathaniel Comfort has pointed out. But technological advances often outstrip the ethical and social means with which to appropriately assess, modify, and utilize them in fair, just, and meaningful ways. So I ask these questions of the sage and thoughtful readers of The DNA Exchange: Just because we can perform prenatal screening for nearly everything genetic, should we? Who should be making this decision?

There are many competing and intertwined narratives about the history of prenatal diagnosis. Let me offer one such narrative to provide ethical and historical angles. During the 1970s and early 1980s, amniocentesis was primarily offered to women of “advanced maternal age” because of the well-documented increase in the incidence of trisomy with maternal age. At the time, in the US women 35 and older represented about 5% of the pregnant population, and this group accounted for about 20% of pregnancies with Down syndrome (this statistic has since changed considerably). While such a policy could be viewed as discriminatory and prejudicial against people with disabilities, the goal of the policy did not seem to be the elimination of genetic disability. Rather, the effect and likely the intent of the policy was to level the reproductive playing field for “older” mothers. During the 1970s, women made great strides in expanding their social and economic opportunities and in taking some measure of control over their reproductive lives with birth control and the availability of safe, legal abortion. Women could now readily attend most colleges and graduate schools, had more career opportunities, and did not feel as much social pressure to retire to motherhood after high school. However, one of the perceived obstacles for delayed childbearing was the greater risk of Down syndrome and other trisomies. Amniocentesis removed this perceived obstacle and consequently women felt freer to delay childbearing until such time as they felt that they and their partners were ready.

Over the decades, mission creep worked its way into prenatal screening. With the gradual incorporation of ultrasound and maternal serum screening into most pregnancies, regardless of maternal age, the detection rate for Down syndrome increased, and critics of prenatal diagnosis raised the specter of the theoretical elimination of all people with Down syndrome. While such an outcome never seemed likely for a variety of social, cultural, individual, and economic reasons, that could be viewed as the intent of prenatal screening. But still, aneuploidy represents only a small portion of all genetic and congenital disorders.

But it is a qualitatively different ethical story with universal NIPT and the expanding number of conditions it can screen for, the prospect of carrier screening for hundreds of genetic conditions for all couples, and talk of whole exome screening of fetuses. That is making quite a profound statement to and about people with a wide range of physical and developmental abilities.

We tacitly assume that the majority of pregnant women want such screening at the same time that we offer it to them. Many patients will  assume that because we are offering it, it must be a good thing. Because genetic counselors’ jobs can depend on the offer and uptake of such services, it affects our views and actions in ways that we often cannot fully appreciate or grasp. To some extent, we offer new testing because labs are offering it and because genetic counselors tend to be early adopters of new genetic tests. As much as we like to think that we are objective assessors of genetic technology who always put the best interests of patients first, the complicated human psyche makes for a messier reality. Our perspectives are distorted by being in the center of the storm. Go ahead and disagree with me if you want, but you are by and large wrong. That’s not me trying to sound superior; motivated blindness is a basic foundational principal of human psychology.

Psychological complexity aside, think of this. The medical profession is already doing a less than stellar job of presenting a realistic and unbiased picture of Down syndrome to parents. Remember, too, that more and more prenatal genetic testing happens without the involvement of a board certified genetic counselor and that parents are often not educated about these conditions until after they have received an abnormal test result. Not exactly the best time to seek out and weigh complicated information. Add a few hundred more conditions less common and familiar than Down syndrome, and you can see the makings of a goddamn mess.

So can there ever be an ethical justification for universal prenatal screening of (theoretically) all genetic and chromosomal diseases? Let me offer some suggestions that could serve as a starting point to address this question. One can argue that this framework or one like it should have been in place decades ago. I agree, it should have. I recognize that for people who are opposed to termination of pregnancy under any condition or for some of the staunchest disability advocates, prenatal screening will never be acceptable unless it somehow improves the lives of people with different abilities and their families. But I ask all sides to at least hear me out.

First, many parties should be involved in the discussion about wide scale prenatal testing, à la Cyprus and thalassemia screening. Prospective users, clinicians, labs, ethicists, religious leaders, legal experts, legislators, and most especially the community of people who are affected directly by the conditions in question (let me add “and others” since no doubt I am forgetting some important stakeholders). You will never get everyone to agree on all of the details, but there should be at least broad consensus about the most critical issues among the majority.

Second, more resources need to be devoted to improving the lives of people with genetic conditions and their families. Every newborn should  be able to live full, rewarding, loving, and enjoyable lives as much as humanly possible. This involves large-scale medical, technological, and social innovations and changes. Improving the social attitudes toward disability is a long, slow, frustrating journey but that should not deter us.

Third, related to the above, prenatal genetic testing should also offer some benefit people with the conditions in questions and their families, other than letting them have the same option as everyone else to terminate pregnancies. Right now, people with disabilities and their families get essentially zero benefit from prenatal screening. Or more accurately, very little research has been done to show any benefits.

Fourth, any new technology or test needs to be vetted by those who do not have a vested professional, financial, or personal interest in the technology or test. Intellectual, research, and financial conflicts of interest have ways of distorting our views in subtle ways that we are incapable of appreciating. This is extraordinarily difficult for us to understand and acknowledge (vide supra motivated blindness).

Fifth, better resources need to be developed for parents to become educated about the medical implications of genetic diagnoses, the range of developmental outcomes, the resources available to manage the condition, and the impact on families, particularly in lower socio-economic populations.

Sixth, this information needs to be provided to parents before they decide to enter the cascade of prenatal screening, not after they receive an abnormal test result. Parents have to carefully decide which if any condition(s) is important to their reproductive and family planning.

If all of these recommendations are in place, this will allow parents to make informed choices about whether or not they wish to go down the prenatal screening pathway and for which conditions. For parents who would never consider a termination under any conditions, they should have the option of screening only for those conditions for which prenatal knowledge can help the child and family, with better medical, psychological, or adaptational outcomes. For parents who have carefully weighed these issues and feel that there are certain conditions that they will choose to avoid if they can, then they should be supported in their decisions with safe, legal, and non-judgmental abortion services. For parents who are not interested in prenatal screening, they should be supported in their decision rather than being made to feel like they are sub-standard parents.

We can ignore my plea, just sit back and see what happens. But this would be a big mistake. Although genetic counselors obviously cannot address this issue by themselves, we are in the ideal position to take the lead in organizing, coordinating, and spearheading the discussion. We owe it to ourselves and to our patients.



Filed under Robert Resta