On April 19 the Food and Drug Administration (FDA) issued a warning about the risks of false results from genetic non-invasive prenatal screening (NIPS).

While health care providers widely use NIPS tests, none have yet been authorized or cleared by the FDA. The agency notes that NIPS test are screening tests, which may only tell you the risk of the fetus having certain genetic abnormalities, but that they are not diagnostic tests, which would confirm or rule out a genetic abnormality.

The NIPS tests currently being offered are laboratory-developed tests (LDTs) that analyze small fragments of fetal DNA circulating in a pregnant person’s blood to determine the risk that the fetus has certain genetic abnormalities.

The FDA said it is aware of reports that patients and health care providers have made critical health care decisions based on results from these screening tests alone and without additional confirmatory testing. Specifically, pregnant people have ended pregnancies based only on the results of NIPS tests.

In January, The New York Times published a story questioning the accuracy of the tests. Dozens of congressional Republicans then wrote the FDA and asked questions regarding the agency’s awareness of problems with the tests.

In the FDA warning, the agency recommended that patients talk to a genetic counselor or other health care provider before deciding to have prenatal testing and discuss which tests to use, including genetic screening tests such as NIPS test.

In addition, the agency urged patients not to use the results of screening tests alone to make decisions about their pregnancy because the results of the tests may not accurately reflect whether the fetus has a genetic abnormality. Additional testing may require invasive procedures to obtain a sample, such as amniocentesis or chorionic villous sampling, which carry a small risk of miscarriage.

The FDA recommended that health care providers discuss with their patients the benefits and risks of prenatal tests, including genetic screening tests such as NIPS tests. Providers should not use the results of screening tests alone to diagnose chromosomal abnormalities or disorders.