Globe story on non-invasive prenatal testing offers murky argument.

An ominous headline in The Boston Globe on Dec. 14 promised a good, tough investigative story: “Oversold prenatal tests spur some to choose abortions,” it read. That seemed to be a story that would indict the marketing of the tests. Or perhaps it was suggesting that the tests are not accurate–prenatal testing does indeed lead some women to have abortions when the tests show chromosomal abnormalities in the fetus.

I was eager to read on. Was the Globe trying to say that some women had abortions when their fetuses were healthy? It wasn’t clear.

The story begins with an extended anecdote concerning a woman who was told, on the basis of a screening test, that her fetus had Edwards syndrome, a severe chromosomal disorder marked by all or part of an extra copy of chromosome 18, known technically as trisomy 18. Daley writes that the woman “said she wanted to terminate the pregnancy immediately.” The woman’s doctor put her in touch with a nurse who found a doctor who could do the abortion the following morning.

The anecdote was going to conclude, I expected, with the woman discovering after the abortion that her fetus had been normal–that the test result had been wrong. And we would be off and running on a story indicting the tests for an unreasonably large error rate.

But no. Her doctor called back and told her to wait. The woman then “had a diagnostic test and learned her son did not have Edwards syndrome,” Daley writes. And she didn’t have an abortion.

Isn’t this the way the system is supposed to work? A screening test finds a potential problem, but a more sophisticated test–we’re not told what that was–shows that there isn’t a problem. Whom are we indicting here? Admittedly, the doctor seems to have been too quick to refer the woman for an abortion. But that is not an indictment of oversold tests, which is what Daley’s story seemed to be about.

Here, in Daley’s fifth graf, is what she says the story is supposed to be about:

Sparked by the sequencing of the human genome a decade ago, a new generation of prenatal screening tests, including MaterniT21, has exploded onto the market in the past three years. The unregulated screens claim to detect with near-perfect accuracy the risk that a fetus may have Down or Edwards syndromes, and a growing list of other chromosomal abnormalities.  

We reasonably expect her to follow that with reporting that shows this claim of accuracy is false. Instead, we get this:

Hundreds of thousands of women in early pregnancy have taken these tests — through a simple blood draw in the doctor’s office — and studies show them to perform far better than traditional blood tests and ultrasound screening.

What? These tests are good? No. Daley writes that “a three-month examination by the New England Center for Investigative Reporting has found that companies are overselling the accuracy of their tests and doing little to educate expecting parents or their doctors about the significant risks of false alarms.” (The story is the product of a partnership between the Globe and the New England Center for Investigative Reporting, based at Boston University.)

Daley then starts to parse the numbers, and she does give us reason to think that the accuracy of the tests is being oversold. But the facts are murky; we don’t know whether the tests are leading to the abortion of healthy fetuses. And the web seems to be full of information discussing the accuracy of the tests, which makes this less of an investigative story than it claims to be.

Evidence on whether healthy fetuses are being aborted “is building,” she writes, noting that Stanford has found three cases of healthy fetuses being aborted. But she doesn’t give us any details on those cases, nor does she talk to the families involved. She also writes that 6.2 percent of women in one study terminated pregnancies without getting an amniocentesis as a follow-up to the screening test. But did they all act on the basis of the screening, or could other factors have been involved? We don’t know. There are many reasons women choose to terminate a pregnancy.

You might be wondering, as I was, exactly which prenatal tests we’re talking about. Daley tells us that these tests are done on blood from the mother, but nowhere does she explain what is going on, which is this: These tests are designed to identify fetal abnormalities based on fetal genetic material circulating in the mother’s bloodstream. If you Google “non-invasive prenatal testing,” you will find a wealth of information about these tests. Daley uses that term, but she doesn’t explain how the tests work, or how errors could arise. Nor does she make clear the differences between screening and diagnosis. She briefly mentions amniocentesis, but doesn’t explain why it can be a more accurate test.

Daley reports that the FDA does not regulate these tests. And it’s reasonable to assume that the companies that make them are pushing them–that’s what companies do when they have products to sell. But if anybody here is guilty of something, it seems to me to be the doctors who are ordering these tests without understanding exactly what they show or without knowing how to properly counsel patients so the chance of a mistake is as low as it can possibly be. (The physicians’ group Society for Maternal-Fetal Medicine worries about this, too, as it wrote in response to the Globe article.)

The New England Center for Investigative Reporting at Boston University says on its “about” page that it “is a nonprofit investigative reporting newsroom based at Boston University and at the studios of WGBH News,” and that its mission “is to ensure the survival of serious, in-depth investigative journalism in New England and to train a new generation of investigative reporters.”

I count nine people on the staff, including Thomas E. Fiedler, Dean of the College of Communication at Boston University. Its blue-chip advisory board includes such luminaries as Fiedler, a former executive editor of the Miami Herald and one of the Herald reporters who busted the presidential candidate Gary Hart in 1987; Bob Giles, former curator of the Nieman Foundation for Journalism at Harvard University; and Benjamin Taylor, a former executive editor and publisher of the Boston Globe.

These seem to be people clearly qualified to pursue investigative stories and be tough watchdogs. But they didn’t do well on this story. (Libby Copeland‘s recap of the story at Slate is shorter and clearer.) Daley, according to her bio, “covered the environment, science and education for almost two decades at The Boston Globe and won numerous awards for her work including being named a Pulitzer Prize finalist.”

Considering her experience, this story should have turned out better.

-Paul Raeburn

2 Replies to “Globe story on non-invasive prenatal testing offers murky argument.”

  1. Dr.K.SParthasarathy

    Full page, colorful advertisements on Genome mapping appeared in many leading dailies in India a few months ago, some claiming virtues of the test. Unfortunately though specialists are available in India, none cared to challenge the over selling of genome mapping in diagnosing diseases including cancer

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