The trade-offs of prenatal testing for Down syndrome

Set of Let's Make A Deal

Set of Let’s Make A Deal

In the first article in the January 2015 edition of Bioethics devoted to prenatal genetic testing, Jenny Hewison addresses the psychological trade-offs pregnant women must make with prenatal testing decisions.

Jenny Hewison is Professor of the Psychology of Healthcare at Leeds University‘s School of Medicine in England. She has published several articles of her research on prenatal testing for various conditions, including Down syndrome.

She has the first article in the edition of Bioethics devoted to prenatal genetic testing. Hewison focuses on the trade-offs women must make when making decisions about prenatal testing. I’ll do my best to summarize her points and then offer my comments on her article at the end.

Trade off 1: Diagnostic certainty vs. risk of miscarriage

This has always been the challenge of prenatal testing: in order for a pregnant woman to know for certain whether she is carrying a child with a genetic condition, she must put her pregnancy at risk to get that diagnostic certainty.

Non-invasive prenatal testing promised to end this trade-off by providing diagnostic results, but it has yet to receive that level of accuracy. Instead, as Hewison notes:

the best non-invasive test still picks out a lot of babies who turn out not to have Down’s syndrome (‘false positives’, in test parlance) as well as ones that do.

As such, non-invasive prenatal screening is just an “add-on” test. Under the United Kingdom’s screening program for Down syndrome, NIPS will be offered as a second screen to those moms already considered high-risk–as is recommended by most professional medical organizations. Therefore, women will still have to risk a miscarriage to know for certain if their child has a genetic condition.

Trade off 2: Information of different conditions vs. risk of miscarriage

The new testing now provides information about more conditions that expectant moms may not have expected being tested for when they agreed to prenatal testing. NIPS laboratories have expanded the list of conditions their tests detect, e.g. sex aneuploidies like Turner or Klinefelter syndromes, and micro deletions, like DiGeorge syndrome (though no professional guideline recognizes NIPS as being accurate for these additional conditions).

Hewison notes:

These developments are driven by technological advance, not by a desire to respond to what women want, and in fact surprisingly little is known about the information that people do want regarding conditions other than Down’s syndrome.

By increasing the number of conditions the women may find out their children have, it expands on trade-off 1’s dynamic of choosing whether to know for sure from diagnostic testing, but at the risk of losing the baby. These other conditions are likely less well-known to expectant women than Down syndrome, and for some, notably the sex aneuploidies, the range of disability is broad, from noticable to almost non-detectable. These expanded conditions will then challenge women’s views on what they consider disabling to such a degree that they would consider ending their pregnancy. In Hewison’s words:

For a proportion of women, accepting an offered test will require them to confront some long-held attitudes to disability and to ending a pregnancy, and that can be a real shock.

Turning to the even more stressful decision to continue or end a pregnancy, at present nearly all the people facing that decision wanted diagnostic information strongly enough to undergo an invasive test. Termination rates are high in this group – perhaps unsurprisingly – but ‘new recruits’ would not be so self-selected, and consequently may find decision-making more stressful.

Trade-off 3: Avoiding a birth vs. ending a pregnancy

The final trade-off that Hewison addresses is for a smaller population of pregnant women, but one that is expanding: those going through an IVF cycle and having preimplantation genetic diagnosis (PGD).

As recounted at this post, PGD is where an embryo developed via IVF, colloquially a “test tube baby,” has a cell removed; the cell’s DNA is genetically tested; and then you have a diagnosis of that embryo’s genetic make-up, identifying any genetic conditions otherwise tested for prenatally. Couples can choose, then, to implant those embryos that did not have a PGD result for a genetic condition. Therefore, couples are choosing to avoid a pregnancy with a genetic condition by not having the affected embryo implanted versus terminating their pregnancy after an amniocentesis result shows their child has a genetic condition.

By removing the ethical issue of abortion, Hewison is noting that this changes the trade-off dynamic for what is considered disabling enough for a mother to decide to terminate her pregnancy. Hewison shares the result of one of her studies:

In other words, for the majority of people, whether they would wish to avoid the birth of a child with a particular condition or not depended on the condition AND on the action they would have to take.

Meaning, that if they could avoid a certain condition through PGD rather than having to terminate their pregnancy, the list of conditions they would choose to avoid grew.

Challenges: information and informed decisions

Hewison wraps up her piece by addressing what is needed when parents are faced with these trade-offs:

Essentially, any information that is provided to all pregnant women, but which aims to meet the needs of individuals, must have three essential properties: first, it must make absolutely clear that all points of view and all decisions will be respected; second, it needs to give enough information, at each stage of the pathway, to make meaningful the decisions that women have to take at that stage; and third, it needs to make clear that support in reaching a decision, and after it has been made, will be available as and when required.

In the end, she concludes that what will be needed is the same as what is currently needed for informed decisions about prenatal testing. Hewison recognizes, though, that the second and third measures–information and support–will likely be more difficult to provide as NIPS expands the number of conditions which women can test for.

My critique

Hewison knows the current system isn’t done well, but prescribes the same treatment that she acknowledges will likely not be enough. How is that ethical care for pregnant women?

Hewison is addressing the United Kingdom’s prenatal screening system, focusing on Down syndrome. She explains how whether a traditional screen is considered “positive” or “negative” is based on an arbitrary standard being set, e.g. a screen below 1-in-200 is considered “positive” and above, “negative.” Hewison writes how raising that standard to, say, 1-in-1,000 would result in more “catches”–those pregnancies actually carrying a child with Down syndrome. But raising the standard would also result in more “false alarms”–more false positives.

Those terms are jarring to read as a parent whose daughter has Down syndrome. I do not like thinking of my daughter being considered by a professor of psychology of healthcare as something to be “caught” by a state-run testing program or that other parents would have a “false alarm” if they were told their daughter may be like mine.

I’m not trying to be overly sentimental by describing these words as jarring.

Rather, my point is that these terms are commonly used with prenatal testing for Down syndrome.

And that’s the problem.

The point of Hewison’s article is that with more conditions able to be tested for, it will challenge parents’ ideas about whether they would terminate their pregnancy for this condition or for that one. As Hewison acknowledges:

Focussing on technology tells us what’s possible, not what’s desirable or indeed what’s desired. The difference between the trisomies highlights the more fundamental question: which conditions are considered sufficiently serious to justify prenatal testing? And by whom?

Except, doing the same to address the same challenges which has not changed anything will only result in more of the same: there won’t be a discussion about what conditions justify prenatal testing. Instead, as NIPS labs expand their panels, those additional conditions will become the next conditions that are tested for, simply because it is possible, without reflection of what is desirable or desired.

And, then five years from now (or sooner), Hewison or someone else will be describing other conditions as “catches” and “false alarms” in the prenatal screening program.

NIPS provides the opportunity to reconsider the ethics of prenatal genetic testing. Instead of calling for “wash-rinse-repeat” while acknowledging mere information and support isn’t enough, perhaps its time to suggest a change in how prenatal testing should be done ethically and address at least two trade-offs not considered by Hewison, but ones which would change the game of how prenatal testing is currently done.

Trade-off 1: A wanted baby vs. a contingent pregnancy

The fundamental trade-off that women have to make when considering prenatal testing is whether they will receive information that will change their pregnancy from a wanted baby to a contingent pregnancy, one that they might terminate.

The few studies of women who have selectively terminated for Down syndrome report that overwhelmingly women consider their pregnancy wanted and their fetus a baby, with moral status. Too often, though, prenatal testing counseling does not begin with the end in mind.

Hewison begins her article by candidly stating:

Probably the main purpose of reproductive technologies is to enable people who choose to do so to avoid the birth of a baby with a disabling condition.

Yet, women are often surprised at being confronted after going through screening and diagnostic testing with only then being asked if they wish to terminate their pregnancies. This is what causes prenatal testing to be a “gradual trap“: just accept screening for reassurance, then diagnostic testing hoping to confirm a false positive, and then, and only then, when the diagnosis is positive, be asked whether they want to schedule an abortion. An abortion, again, of what women say is a wanted baby.

Perhaps if the whole process started off with:

I’m going to offer you some tests that will give you information about your baby’s genetic make-up and whether your child will be born with a disability. Nothing can be done to change this; your child’s genetic condition happened at the time of conception or soon thereafter. Now, knowing beforehand can allow you to prepare for the birth of your child and learn more about the condition if you choose to continue your pregnancy. But, I will ask you if you receive a prenatal diagnosis whether you will abort your baby. Knowing that you may have to make that decision if you decide to go down this path, do you want to have prenatal testing?

Hewison writes of how expanded panels of testing will challenge women to consider what is disabling and what is not. But ultimately they will be faced with the same question: are you willing to consider terminating a wanted pregnancy or aren’t you?  Perhaps if this decision was addressed at the outset, then at least women will avoid the gradual trap and make their decisions knowing full well what ethical issue they may be confronted with in the end.

Trade off 2: Fund prenatal testing vs. fund support services

The other trade-off that plays into a woman’s decision is whether she will pay for prenatal testing. In the United Kingdom, prenatal testing is paid for through the taxpayers funding the National Health Service, but there isn’t an immediate charge should a woman opt for traditional screening and diagnostic testing.

However, as Hewison notes, for an English mother to have NIPS as a first screen, that is not covered by the NHS. Some women are making a trade-off: to not have NIPS as a first screen and save some money, or decide NIPS as a first screen is worth the out-of-pocket expense.

This economic trade-off is one that is largely removed for prenatal testing in Western countries because prenatal testing is subsidized through state health care programs or covered through private insurance. But what if it wasn’t?

Then, women would have a very real assessment of how much they value prenatal information. It’s a very different discussion with the physician when they offer prenatal testing and only a $20 co-pay is required, versus paying $2,000 for NIPS or more for invasive testing.

Further, how different would society be if the millions of dollars poured into prenatal testing were instead funding social services to support the individuals with the disabling condition that is being tested for?

As Hewison notes:

The majority of women undergoing an invasive test for Down’s syndrome learn that the baby does not have the condition.

This is simply because the tested-for genetic conditions remain rare: less than 1% incidence rate of all pregnancies for any given condition.

So, then, what if that money that went for the screening and invasive testing–millions upon millions, year upon year–instead went to support programs for those with the tested-for conditions.  If that money went to providing more early intervention therapies, more inclusive school programs and adaptive technology, more vocational skills training, and more community living opportunities, wouldn’t that also change how disabling those conditions are considered by society?

It’s what’s happened with Down syndrome. As I’ve written before, with individuals with Down syndrome being welcomed into the community and out of institutions, their lives have surpassed what most would have imagined just in the span of my lifetime.

NIPS provides that opportunity to reevaluate how scarce public health dollars are being spent. There are counterarguments based on the bioethical principle of justice that would say it is not fair for the well-to-do to be able to test and selectively terminate pregnancies of children with disabilities while the less-well-off are further burdened by having to care for a child with a disability. And while a reply would be that those less-well-off would also benefit by having more robust public supports, I’m not saying no public funds should be spent on prenatal testing.

Instead, I’m simply noting that there are some fundamental trade-offs not addressed by Hewison that if they were, perhaps we would achieve a more ethical administration of prenatal testing.

If women were confronted with these two additional trade-offs, perhaps they would make more informed decisions about why they would accept prenatal testing and how much they valued that information.


  1. anticancer says:

    Sequenom will soon release a liquid biopsy test
    you like this product more?

    • While not relevant to this post, my response is that I would welcome any product accurately marketed to patients and physicians that delivers results in accurate language with the recommended information also provided as recommended by professional guidelines. So far, Sequenom does none of these.

  2. Thanks, as always, Mark, for your measured and thoughtful response. I am so grateful for this blog!

    • And, I’m grateful for you having read what is likely the longest post so far on this blog! 😉 (Plus, I really appreciated your recent article sharing the experience of expectant moms being told, incorrectly, that the new test is “99% accurate.”)

  3. The question of funding a national screening program versus support services is an interesting one. In the UK it costs 38,000 pounds to prevent the birth of a child with Down syndrome, but they reckon it is good value because it is cheaper than providing care. To see the full picture, you need to consider the investment costs to find a DS pregnancy, rather that the costs per typical pregnancy. Because that is why it is funded by the state. Those stats are in my blog

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