Human Nature

Fetal Flaw

The abortion politics of new prenatal tests.

Prenatal genetic tests can now be performed with a simple blood draw
Prenatal genetic tests can now be performed with a simple blood draw

Photo by Hoang Dinh Nam/AFP/Getty Images.

Today, if you’re pregnant with a defective fetus, you won’t know about the problem till you’re well along. At 10 to 12 weeks, you can get chorionic villus sampling, which involves extracting tissue from the placenta by going through your abdomen or inserting a tube through your cervix. At 15 weeks or so, you can get amniocentesis, which involves sticking a long needle through your belly to draw amniotic fluid. Both tests are uncomfortable, and in one case out of every 100 to 200, they cause a miscarriage.

That’s now changing, thanks to noninvasive prenatal testing (NIPT). As Mara Hvistendahl explained recently in Slate, companies are developing tests that can estimate the risk of a defective pregnancy from fetal DNA in the mother’s own blood, extracted by a regular needle from her arm, like any other blood draw. That means less risk of miscarriage, less stress, less discomfort, less hassle, and lower cost. It also means earlier detection. This week, at a conference at Stanford Law School, companies working on the technology said their tests could screen for defects at 10 weeks. But informally, the expected threshold for NIPT is seven to eight weeks, and possibly five.

What’s going to happen to prenatal testing in this country when you can get it earlier, cheaper, and more easily? What will happen to the abortion rate and the population of families affected by, say, Down syndrome? Will pro-lifers and disability groups freak out? Will states restrict the new tests?

I don’t think so. I’ve been looking at recent polling data, as well as the science and practice of prenatal testing. The interests lined up behind NIPT are formidable: parents, disease lobbies, biotech and medical companies, insurers, and governments that fund health care. And on the other side, pro-lifers will have a much harder time fighting NIPT than they’ve had fighting abortion.

Americans have always expressed more sympathy for aborting defective fetuses than for abortion in general. In recent polls by Gallup and Fox News, narrow majorities supported legal abortion in the case of fatal defect or physical or mental impairment. Pro-lifers hope to prevent this practice from spreading to less dire conditions. Four years ago, the Ethics and Public Policy Center commissioned a poll showing that 57 percent of U.S. adults thought abortion should be allowed if prenatal tests indicated fatal disease, but only 20 percent thought it should be allowed if tests indicated a “serious, non-fatal” condition such as Down syndrome.

The problem for pro-lifers is that prenatal testing doesn’t work this way. It combines some issues and separates others in ways that confound moral distinctions. To begin with, there’s an obvious medical and business logic to screening for many conditions in a single test. Once you’ve assembled fetal DNA from fragments in the mother’s blood, you might as well check it for Down syndrome as well as cystic fibrosis. So while some people might condone testing for one disease but not the other, it isn’t clear how you’d write, pass, or enforce a law to impose that distinction.

Nor is it clear how you’d impose a distinction between one purpose and another. Take sex selection. The EPPC poll, like others, shows overwhelming opposition to permitting abortions of fetuses just because they’re female. Yesterday, a majority of the U.S. House of Representatives voted to outlaw such abortions. But doctors test for fetal sex all the time. They do it because some families carry X-linked disorders, which produce disease in boys, since males don’t inherit a second X chromosome to counteract the first one. If sex is a medically legitimate trait to test for, how will you police which women can be told they’re carrying girls, and which can’t? And once they’re told, how can you connect that disclosure to their subsequent decisions? It’s not like they’re all going to announce to an abortion provider that they want the fetus out because it’s a girl.

Look closely at the question in the EPPC poll. It doesn’t ask whether testing should be allowed for nonfatal conditions. It asks whether abortions should be allowed based on the test results. Why? Because if you don’t mention abortion, Americans don’t object to the tests. In a 2004 survey by the Genetics and Public Policy Center, 60 percent of respondents approved of prenatal genetic testing for diseases that wouldn’t even show up in the fetus till it reached adulthood. Fifty-one percent approved of testing for fetal sex. In every scenario, support for testing fetuses exceeded support for testing pre-implantation embryos. That’s a pretty clear sign that the respondents weren’t thinking about abortion.

The separability of testing from abortion, coupled with the bundling of testable diseases and the ambiguity of how the findings will be applied, makes moral regulation of prenatal testing a logistical nightmare. It puts pro-lifers in the politically untenable position of opposing information and health care, not just abortion.

Look what happened to Rick Santorum two months ago when he criticized prenatal testing as a gateway to abortion. In a poll published by National Journal, a 2-to-1majority of Americans—60 to 30 percent—affirmed not just that prenatal testing should be permitted, but that insurers should be required to pay for it. They took this position even after hearing the anti-abortion argument as part of the poll question. And in a brutal exchange on Face the Nation, Bob Schieffer demolished Santorum’s position. “Senator, do you not want any kind of prenatal testing?” Schieffer asked. “Would we just turn our back on science” and say “it’s best not to know about these things ahead of time?” Santorum was forced to cave.

Ugly as that episode was, an attack on NIPT could get uglier. Santorum was challenging amniocentesis, which takes place in the second trimester. NIPT takes place in the first trimester. Morally, this makes NIPT far more palatable, since the fetus is less developed. Politically, it puts pro-lifers in the awkward position of opposing a technology that could replace second-trimester abortions with first-trimester abortions. Last year, Gallup found that while only 24 percent of Americans thought abortion should be legal in the second trimester, 62 percent thought it should be legal in the first trimester. An attack on NIPT would defy this consensus that earlier is better. And it would leave pro-lifers with the task of explaining why women should be consigned to tests that produce a measurable rate of miscarriage.

The pro-abortion rights aspect of the backlash could be more explosive. The new tests aren’t just earlier; they’re less invasive. Anyone who opposes them has to explain why women should instead have to endure the tubes and needles of amniocentesis or chorionic villus sampling. Remember what happened earlier this year, when the Virginia legislature passed a bill requiring ultrasound before abortions? A firestorm erupted over the prospect that the bill would require transvaginal ultrasound, in which “a probe … covered with a condom and a gel” is inserted into the vagina. Pro-lifers looked like they were mandating sexual abuse. The governor had to ask lawmakers to remove transvaginal ultrasound from the bill. I doubt Republicans want to replay that fight in a debate over invasive prenatal testing.

That doesn’t mean pro-lifers can’t or shouldn’t do anything about NIPT. The availability of easier, cheaper, earlier tests will almost certainly increase the abortion rate. Pro-lifers might succeed in regulating counseling or insurance practices so that ambivalent women don’t feel pressured to abort. But the best way to separate testing from abortion is to push the technology forward so that we’re fixing defective embryos and fetuses, not just discarding them. Who could be against that?