An excellent piece by Beth Daley from the New England Center for Investigative Reporting called “Overused and Misunderstood” is a must read. It is about the new non-invasive prenatal screening tests offered by companies that claim they are 99% accurate. These screens are done early in pregnancy using only a maternal blood sample giving couples an eariler look at the health of their unborn baby.
The problem is that these are screening tests but are being used as diagnostic tests.
What is the difference? A screen is a test given to a general healthy population and usually has high sensitivity so that any possible problems are flagged. Because of the high sensitivity, false positives are more common. Also, screens are not necessarily approved by the FDA. A screen is always supposed to be confirmed with a diagnostic test. A diagnostic test is designed with high specificity for a particular condition flagged by the screen. It is often more invasive and is meant as a tool to make a definitive diagnosis.
Because these new, non-invasive, prenatal screening tests are being touted as “99% accurate” and having “near-diagnostic accuracy,” parents are skipping the confirmatory diagnostic tests like CVS and amniocentesis and are going straight for abortion if the screen indicates a genetic problem. Daley reports on the Chapmans that almost aborted their healthy son:
Stacie Chapman’s heart skipped when she answered the phone at home and her doctor — rather than a nurse — was on the line. More worrisome was the doctor’s gentle tone as she asked, “Where are you?”
On that spring day in 2013, Dr. Jayme Sloan had bad news for Chapman, who was nearly three months pregnant. Her unborn child had tested positive for Edwards syndrome, a genetic condition associated with severe birth defects. If her baby — a boy, the screening test had shown — was born alive, he probably would not live long.
Sloan explained that the test — MaterniT21 PLUS — has a 99 percent detection rate. Though Sloan offered additional testing to confirm the result, a distraught Chapman said she wanted to terminate the pregnancy immediately….
Chapman spent the afternoon Googling the horrors of Edwards syndrome, with its heart defects, development delays, and extraordinarily high mortality. She was steeling herself for the termination when Sloan called back, urging her to wait, according to Chapman’s medical record.
Chapman had a diagnostic test and learned her son did not have Edwards syndrome. A healthy Lincoln Samuel just turned 1 and has a wide smile that reminds Chapman of her recently deceased father.
The Chapmans are not alone. Daley exposes that:
Two recent industry-funded studies show that test results indicating a fetus is at high risk for a chromosomal condition can be a false alarm half of the time. And the rate of false alarms goes up the more rare the condition, such as Trisomy 13, which almost always causes death.
False alarm half the time.
I really have no issue with these tests IF they were presented to doctor and patient properly. In an ideal world, abortion would not be an option, but early intervention would. In other words, if a genetic anomaly was indicated in a screen, a more accurate diagnostic test would be performed, and then a healing intervention like gene therapy would be attempted. Obviously gene therapy in utero is not yet a therapeutic option for the unborn, but when it is, these screening tests will be a valuable tool.
But if companies are presenting these screens to be as good or better than a diagnostic test, doctors believe them and parents are aborting as a result, then the companies are seriously negligent. Like in this case, which turns my stomach:
And at Stanford University, there have been at least three cases of women aborting healthy fetuses that had received a high-risk screen result.
“The worry is women are terminating without really knowing if [the initial test result] is true or not,” said Athena Cherry, professor of pathology at the Stanford University School of Medicine, whose lab examined the cells of the healthy aborted fetuses.
In one of the three Stanford cases, the woman actually obtained a confirmatory test and was told the fetus was fine, but aborted anyway because of her faith in the screening company’s accuracy claims. “She felt it couldn’t be wrong,” Cherry said.
Obviously no child should be aborted for any reason. But this report is very troubling. How many healthy babies have been ripped from their mother’s wombs because of predatory marketing?
Here are my recommendations:
1. Never confuse a screening test with a diagnostic test. Always get a confirmation with an FDA approved diagnostic test.
2.Get genetic counseling with any positive genetic test, prenatal or otherwise. Request genetic counseling even if your doctor does not suggest it. Doctors often do not know about the intricacies of genetic testing, especially if the tests are new. Genetic counselors are professionals who are up on all the latest genetic tests and will surely know the difference between a screen and a diagnostic test. They are there to guide patients through the maze of genetic testing. I highly recommend availing yourself of their services.