By Emily Mangiaracina
The Food and Drug Administration (FDA) is warning that prenatal screening tests for genetic abnormalities, which lead some women to have abortions, can give “false results” and in some cases have high chances of false positives.
(NIPS) tests, which are designed only to tell a baby’s risk of a genetic abnormality and not to “definitively confirm or rule out” such an abnormality, are often claimed by laboratories to be “reliable,” “highly accurate,” and offering “peace of mind” to patients, the FDA pointed out in a notice issued Tuesday.
However, the FDA “is concerned that these claims may not be supported with sound scientific evidence,” and that in some cases where rare disorders are being screened for, such as when microdeletions are being detected, “there may be a high chance” of a false positive.
Despite a substantial risk of inaccurate results, the FDA said it has been made aware that women have had abortions “based only on the results of NIPS tests.” However, without a confirmatory diagnostic test, “there is no way to know” whether the baby actually had the genetic abnormality indicated by the screening test, the FDA said.
The regulatory agency noted that there are reported cases where a screening test indicated a genetic abnormality that was later found to be nonexistent by a diagnostic test.
According to the FDA, studies show that NIPS test results, when negative, have a greater than 99.9 percent chance of accuracy. However, the rate of accuracy is substantially lower when test results come back positive. In this case, reliability was best for detection of Down syndrome, with a 90 percent chance of accuracy (but still leaving a significant 10 percent chance of a false positive).
However, tests for microdeletion disorders, such as Di George syndrome, have a radically lower accuracy rate for positive results, “with the positive predictive value ranging from about 2% to 30%, depending on the condition,” the FDA wrote.
For this reason, the FDA noted that the American College of Obstetricians and Gynecologists (ACOG) “does not recommend the use of NIPS tests to detect microdeletions.”
The FDA explained that the “increased use” of NIPS tests and “concerns raised in recent media reports” prompted this week’s notice.
A January 1 New York Times report found that microdeletion tests yield about 85 percent false positives. It shared that according to a geneticist, one woman had already had her baby killed in an abortion by the time a follow-up test revealed her baby was in fact healthy. The Boston Globe also quoted a doctor describing three abortions “following unconfirmed positive results.”
The Times found in interviews that eight of 14 patients who got false positives for genetic disorders “said they never received any information about the possibility of a false positive,” and “five recalled that their doctor treated the test results as definitive.” These women described an “agonizing” experience after the positive results, including “sleepless days and nights hiding their bulging bellies from friends.”
Following the Times report, genetic testing company Natera’s stock dropped “as much as 3.5%,” and Frank R. Cruz’s legal practice announced shortly afterward that it is investigating Natera on behalf of investors “concerning possible violations of federal securities laws.”
In light of Natera’s failure to share its actual rate of false positives, Hindenburg Research went so far as to assert that Natera’s revenue growth has been “fueled by deceptive sales and billing practices aimed at doctors, insurance companies and expectant mothers.”
The New York Times found that Natera was not the only genetic testing company that omitted such potentially life-saving information. A review of patient and doctor brochures from eight testing companies, including Natera, Labcorp, and Quest, found that “10 of the brochures never mention that a false positive can happen,” and that “only one mentioned how often each test gets positive results wrong.”
Reacting to the Times report, pro-life leader Lila Rose insisted that such prenatal tests should never be used as an excuse to kill unborn children: “It’s horrific that prenatal tests are used to ‘justify’ abortion,” Rose remarked on Twitter. “Every child, regardless of their health, deserves a chance at life and to be loved.”