Jeffrey Greenberg/UCG/Universal Images Group via Getty Images
According to an investigation by The New York Times, blood tests on pregnant people that look for rare and devastating conditions are often wrong.
The blood testing technology works well for Down syndrome. According to The New York Times, a review of data from multiple studies showed that when NIPT is used to test for rare syndromes, it's usually found in one in 20,000 births.
The tests made by companies like Sequenom have become more popular in recent years. Billions of dollars are estimated for the size of the market. Positive results on the tests are supposed to lead to more extensive follow-up testing, but those tests are expensive, intrusive, and often can't be done until it would be too late for a legal abortion. Many patients don't get follow-up tests and some end up having abortions based on the initial information.
Testing for things that are extremely rare is a statistical challenge. A test that is highly accurate would still find a lot of false positives if it was used on thousands of people to try to find a condition that is only actually there.005 percent of the time. It is difficult to create tests for rare conditions that will not have a lot of false positives.
The New York Times reported that the issue wasn't adequately explained to patients who were sold the tests. The language used by companies developing NIPTs was highly accurate and confident. Many companies did not publish data on their tests performance overall or stressed data from tests that are more accurate. The former director of the FDA's office overseeing medical tests thinks the information they give is misleading.
Lab-developed tests, which are able to skirt some regulatory oversight, are the ones that don't have to be cleared or reviewed by the FDA. Even if it is misleading, they are able to advertise to patients andut the limited data they have in marketing materials.
The full investigation can be found here.
