The Food and Drug Administration on Tuesday warned expectant parents of the risk of false-positive results from a thriving array of prenatal blood tests that screen fetuses for rare genetic disorders.
The report followed a DailyExpertNews survey in January that reported the incidence of false-positive results with some of these tests, known as non-invasive prenatal screening tests, or NIPTs. That article quoted women who received false-positive screening results for extremely rare conditions; highlighted examples of deceptive marketing by companies selling the tests; and described some reports of pregnancies terminated based on screening without a confirmatory test.
The agency warned doctors not to diagnose genetic disorders based on these results alone, and emphasized the need to track positive screenings with more reliable “diagnostic” tests. It said it was “aware of reports” that some women have “terminated pregnancies based solely on the results” of these genetic screening tests.
“While genetic non-invasive prenatal screening tests are widely used today, these tests have not been reviewed by the FDA and may make claims about their performance and use that are not based on sound science,” Dr. Jeff Shuren, the agency’s director of the Center for Devices and Radiological Health, said in a statement.
The tests are taken by more than a third of pregnant women in the United States. But they fall into a category called lab-developed tests, which are not regulated or approved by the FDA. In its security notice, the agency said it was working with Congress “on legislation to establish a modern regulatory framework for all tests,” including the category that includes these displays.
The agency’s warning comes after countless years of tales of misinterpretation of the showings as definitive. But criticism has grown in recent months, with 97 Republican lawmakers sending a letter to the FDA in January, following the Times article.
“This is an area the agency has been working on for a long time,” said Alberto Gutierrez, the former director of the FDA office that oversees many medical tests.
The lack of regulation of tests developed in the lab “has led to many cases where the labs have claimed more than they should based on the available evidence,” he added.
The warning will not affect manufacturers of prenatal tests. But it urged them to submit their products for voluntary approval. A spokeswoman for the agency declined to say whether it is currently working with manufacturers in this area.
In just over a decade, lab experiment testing has moved on to a major industry, with companies like Labcorp and Quest Diagnostics, alongside many start-ups.
A major test maker, Natera, said it conducted more than 400,000 screenings in 2020 for one type of condition called microdeletions — the equivalent of testing about 10 percent of pregnant women in America. During a conference call with investors in 2021, it revealed that 75 to 80 percent of its core prenatal testing business involved microdeletion screening.
Immediately after the FDA warning was issued on Tuesday, Natera’s stock fell more than 7 percent, but it had regained much of its value by mid-morning Wednesday.
“Natera fully supports the FDA’s communications regarding NIPT and has long believed that educating patients and healthcare providers about its strengths and limitations is essential to patient care,” the company said in a statement.
Myriad, another test maker, said it would support a role for the FDA in regulating lab testing. Labcorp said it appreciated the FDA’s guidance on the subject and that “screening tests should be followed up with diagnostic tests as needed.”
Other major test makers, including Quest and BioReference Laboratories, did not immediately return requests for comment.
The Times survey included a review of 17 brochures from companies that sell prenatal screenings. At the time, 10 of the brochures did not mention that a false positive could happen. Mr. Gutierrez reviewed some of the materials and described them as “problematic” and “misleading.”
“Many labs offering these tests claim that the tests are ‘reliable’ and ‘highly accurate’, offering ‘peace of mind’ to patients,” the agency wrote, citing examples published by The Times in January. concerned that these claims may not be supported by sound scientific evidence.”
After reviewing the scientific literature, the agency said that prenatal screening tests “generally perform well to rule out conditions,” but are less reliable if they produce positive results. The most reliable positive results are for Down syndrome. For more rare genetic conditions, caused by tiny missing fragments of chromosomes known as microdeletions, the agency found that a positive screening result can be a false positive between 70 and 98 percent of the time.
Their findings are consistent with the Times article, which identified five microdeletion studies in which about 85 percent of positive results are false positives.
“This is a strong response,” said Liz Richardson, who leads The Pew Charitable Trusts’ health care products project and author of reports calling for regulation of prenatal testing. “In my opinion, it still puts a great burden on the consumers and the healthcare providers to know how to interpret these tests, when really it should be the burden on the company to communicate in a truthful and non-misleading way” she added.
“While this is a helpful first step, I think there is a need for more comprehensive reform of the FDA’s oversight of these tests, as well as other lab-developed tests.”
A bill to provide additional oversight is currently in Congress. The VALID Act is a bipartisan bill in both chambers that would give the FDA the authority to regulate lab-developed tests in the same way as diagnostic tests. The bill will go to committee this spring.
In a statement, Texas Representative Chip Roy, one of the authors of the congressional letter and an opponent of abortion, praised the FDA’s announcement as “another step toward protecting life.”
“Parents deserve full information when making complicated medical decisions for their children, especially when these tests can be a matter of life or death,” he said.
Susan C. Beachy research contributed.