A new kind of prenatal testing is growing in popularity. It’s noninvasive, and checks for genetic disorders with minimal risk and high accuracy. Instead of collecting DNA from the womb with big needles, it sequences cell-free fetal DNA that floats in the mother’s bloodstream during pregnancy.
With just a simple blood sample from mom, tests using cell-free DNA (sold in the United States under brand names MaterniT21 Plus, Panorama, Verifi, and Harmony) can flag a variety of chromosomal conditions in a baby, such as trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome). They may also check for sex gene disorders like triple X and Klinefelter syndromes.
All this testing could bode well or ill for children, depending on their parents’ viewpoint.
Noninvasive tests are safer for the baby than amniocentesis and chorionic villus sampling, which may occasionally cause a miscarriage. Noninvasive tests can be performed early in the pregnancy, too, at nine or 10 weeks. They are advertised to be highly accurate, detecting Down syndrome, for example, in 99 out of 100 cases.
The potential problem is the motive for prenatal testing in the first place. Why offer testing for a disorder you can discover at birth? Often, the answer appears to be so women can make an “informed decision” whether to “continue” their pregnancy—or abort.
Donna Harrison, the executive director of the American Association of Pro-Life Obstetricians and Gynecologists, points out that when doctors test for a disease like strep throat, they normally have the goal of treating and curing the patient. “There is no drug or treatment that can modify the genome of the fetus, so the fetus receives no benefit,” she says of the prenatal testing trend. “And, what if the test is wrong?” (They do give false positives occasionally.)
Parents who discover their unborn child is positive for a chromosomal disorder often decide to abort. When they discover Down syndrome by prenatal diagnosis, up to nine out of 10 parents choose to terminate, according to some studies. As prenatal tests become less invasive, more convenient, and more common, it’s reasonable to think more parents will be prompted to abort an “imperfect” child.
Not everyone views the new tests negatively, though. In 2011 Ashley Newman of Spring, Texas, became one of the first women to use a noninvasive prenatal test. Halfway through her pregnancy, a MaterniT21 test showed Newman’s baby boy had Down syndrome.
Newman says it was important for her and her husband to know the diagnosis in advance. “Regardless, we weren’t going to end the pregnancy.” She grieved over lost expectations, but also spent time learning about Down syndrome, informing family members, and ensuring her hospital would provide extra fetal monitoring for heart defects or intestinal problems associated with the condition.
Being prepared made the birth less overwhelming, she says. “My son was born, and it was a celebration. We were ready.” Eli, whom she describes as a “perfect son” knit together by God, will turn 2 in April. A MaterniT21 test for Newman’s third child, due in April, came back normal and revealed the baby’s gender (a boy) at just 12½ weeks gestation (more at barryandashley.wordpress.com).
The provider of MaterniT21 expected to sell 150,000 tests last year. Other brands are selling tens of thousands more. Whether used to improve a birth or prevent one, noninvasive prenatal tests are coming to an ob-gyn office near you.