Some say prenatal tests aren’t as accurate as believed

News
Sonogram_98036

BUFFALO, N.Y. (WIVB) – Some medical professionals disagree about the accuracy of newer prenatal tests in diagnosing potential health issues by detecting chromosomal defects in unborn children.

Kymberly Cochran is a mother who received word that her child had tested positive for Down Syndrome. The phone call she got still haunts her. “Did the blood work, did all of that, and then I got the phone call. The genetic counselor called me and told me ‘Oh well, your kid tested positive for Down Syndrome,’ and I just started crying,” she told News 4.

Cochran was living in Kansas at the time and had no idea she’d even taken a test for Down Syndrome. At her 16-week appointment she had an ultrasound where she was told the baby was measuring on track.

“He was very nonchalant about it actually. He told me based on the blood work that I had the option of terminating the pregnancy up to 26 weeks due to the test results because the ultrasound can’t be 100%,” Cochran explained.

Cochran and her ex-husband decided that no matter what they were keeping the baby. A few months later her daughter Katelyn was born. “She was perfectly healthy,” Cochran said. Now 3-years-old, Katelyn is a bubbly little girl.

“There probably have been perfectly healthy babies that were not given a chance,” Cochran worries.

Beth Daley writes for the New England Center for Investigative Reporting. She said, “It became pretty clear to me women were actually acting on screens. At Stanford University they had 3 cases of women aborting healthy fetuses.”

Daley found that one medical company reported 6.2 percent of women had an abortion based solely on the newer blood tests which have exploded onto the market since 2011. Those tests detect the baby’s risk of Down Syndrome, and Trisomy 18 & 13; two chromosomal defects which are nearly always fatal.

But Daley says those tests aren’t accurate. She references a Quest Diagnostics study that found a positive test result for Trisomy 18 or Edward’s Syndrome is accurate around 64 percent of the time for older women. The number is even lower for younger women; only 40 percent accurate. “When you get a result saying something is really wrong, women really need to realize that does not mean something is wrong. Despite everything they’re hearing from all the marketing material that the test is 99 percent accurate,” warned Daley.

“We wouldn’t be using it if those numbers weren’t accurate,” countered Dr. Jeffrey Johnson, University at Buffalo’s Chief of Maternal-Fetal Medicine and Kaleida’s Medical Director of the Prenatal Center of Western New York.

He’s never had a false positive, he says. According to Johnson, the Quest study only looked at 25 women; not enough to come to a conclusion about the tests. “We have much larger studies that show much higher detection rates than this. Most of the other studies that have been published in the New England Journal of Medicine are posting rates of 95-98 percent for Trisomy 18.

Still, both Daley and Dr. Johnson agree the tests are for screening purposes only, alerting of a potential problem and should always be followed up with an amniocentesis.

Questioning the accuracy of the results, some women are opting out of the tests all together. “I want to live a stress-free pregnancy, that’s important. Stress can really affect the baby so stress-free and whatever happens, happens. That’s the way it’s meant to be,” said new mother Amber Fuller who opted out of the testing.

“Don’t automatically assume that you have to abort the pregnancy because they do come out extremely healthy,” said Cochran.

Dr. Johnson says not all women should be receiving this test. It’s meant for women 35 years and older if they’ve had an abnormal screening test or ultrasound abnormality. The problem is when some doctors aren’t fully educated about the screening, like in Cochran’s case. She was only 22 years-old when she was pregnant.

Copyright 2021 Nexstar Media Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Trending Now