Older women who become pregnant and those women with a predisposition to pass on a genetic defect to their babies are frequently encouraged to use new noninvasive blood tests that doctors say can be up to 99 percent accurate in predicting chromosomal abnormalities. Hundreds of thousands of women have used these tests since they first appeared on the market in 2011, and studies have found them to be more accurate than other standard early-pregnancy screenings.
But, positive results can be wrong 50 percent or more of the time. And an investigation by the New England Center for Investigative Reporting published in the Boston Globe found that “likely hundreds” of women are aborting fetuses based on this new generation of testing, according to a report by The Today Show. One company reported a 6.2 percent abortion rate based on screening results alone — and without further testing, there is no way to know how many of those may have been due to a false positive, according to the report.
Zachary Diamond and Angie Nunes of Portland, Oregon, nearly terminated their pregnancy because of their test results. Their doctor urged Angie — who has muscular dystrophy — to have the test he called “99 percent accurate in predicting chromosomal abnormalities.” The test revealed that her foetus had Trisomy 18 – Edwards Syndrome, a painful genetic condition that is nearly always fatal. The couple was told to prepare for the worst. Only after a 16-week ultrasound and a second screening test did doctors realise Angie was carrying a normal baby. Son Solomon is a healthy 6-month old. Their story, and others like it raise serious questions about both the accuracy of these new tests and the difficulty physicians have in interpreting the results.