FDA warns that some prenatal screening tests can generate false results

  • April 29, 2022

The growing – and sometimes inappropriate – use of these tests prompted the warning, according to FDA.  These tests, which fall under the category of laboratory-developed tests (LDTs), are not subject to premarket review by FDA and are accorded enforcement discretion under the Medical Device Amendments of 1976.

“While genetic non-invasive prenatal screening tests are widely used today, these tests have not been reviewed by the FDA and may be making claims about their performance and use that are not based on sound science,” said Jeff Shuren, Director of the FDA Center for Devices and Radiological Health (CDRH).  “Without proper understanding of how tests should be used, people may make inappropriate health care decisions regarding their pregnancy.  We strongly urge patients to discuss the benefit and risk of these tests with a genetic counselor or other health care providers prior to making decisions based on the results of these tests.”

FDA warns these tests should be used for screening purposes only as they “only provide information about the risk that a fetus may have a genetic abnormality, and additional testing may be needed to confirm whether or not a fetus is affected,” said the Agency.  The Agency found that many test developers advertise these products as “reliable” and “highly accurate,” and offering “peace of mind” for users, yet these claims “may not be supported with sound scientific evidence.”

When such tests are used to screen for a very rare condition, “a positive screening result may be more likely to be a false positive than a true positive and the fetus may not actually be affected.  In other cases, a positive screening result may accurately detect a chromosomal abnormality; however, that abnormality is present in the placenta and not in the fetus, which may be healthy,” according to an FDA statement.

Users have ended pregnancies based on these screenings “without understanding the limitations of the screening tests and that the fetus may not have the genetic abnormality identified by the screening tests,” FDA noted.  The Agency said it is continuing to work with Congress to establish a regulatory framework for LDTs, which include NIPTs.

The warning follows a February 2022 hearing where lawmakers expressed concern about the lack of regulatory oversight of these tests.  The hearing was prompted by New York Times investigation which found the NIPTs that screen for a rare genetic condition often gave false results.

REFERENCE:  RAPS (Regulatory Affairs Professional Society) Regulatory Focus News Article (2022 4); 20 APR 2022; Joanne S. Eglovitch

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