Learning about the genetic health of an unborn child could soon be as simple as giving blood.
A new prenatal test is slated to hit the market this summer that requires nothing more than a sample of a pregnant woman's blood for doctors to analyze the DNA of her developing fetus.
Current methods to collect fetal DNA, such as amniocentesis, involve an intrusion into the uterus that can trigger a miscarriage – a risk that makes many couples refuse the procedure. But after 30 years of effort, science appears to be on the cusp of delivering a safe, non-invasive test that can detect Down syndrome and other genetic conditions by capturing the minute bits of fetal DNA in a pregnant woman's bloodstream.
Yet as with most advances in reproductive medicine, the new technology is raising tricky social questions.
While some see it as a better way to prepare parents and hospitals to care for newborns with special needs, others fear it smacks of eugenics as science makes it ever easier to reject a less-than-perfect baby.
Sequenom Inc., a biotech firm based in San Diego, says it will begin selling the first non-invasive prenatal genetic test, pioneered at the University of Oxford, online in June. Meanwhile, researchers at Stanford University have developed a similar version they expect will be available within two years.
Neither test has been tried in large patient studies to evaluate accuracy. But if the promising preliminary results hold up, experts say the tests, which can be performed early in pregnancy, will revolutionize the field.
“This is a powerful technology,” said Doug Wilson, head of the genetics committee of the Society of Obstetrics and Gynaecology of Canada.
“If it can be proven to be as accurate [as current diagnostic methods] it will become the new diagnostic gold standard.
“If it can be done at 10 weeks, instead of 16 weeks, it will relieve the stresses of pregnancy early.”
At the Canadian Down Syndrome Society, however, news of the technology coming to market has only added to stress levels.
“People with Down syndrome are very concerned about the emergence of tests that aim to eliminate them from the world,” said the society's executive director, Krista Flint.
“Down syndrome is a bellwether – if this is an easy test, it is just a matter of time before it's used to determine other things, and sometimes just because we can do something doesn't mean we ought to.”
Scientists have long searched to find a non-invasive way to gather fetal cells from a pregnant woman's blood. But the rare few that exist have been shed off the placenta, and are on their way to dying, Dr. Wilson explained. Adrift in the woman's blood, they burst.
Then in 1997, scientists Dennis Lo and James Wainscoat, at the University of Oxford, pioneered a technique to pick up the fetal genetic material that lingers in a woman's bloodstream even after the fetal cells have died off.
Sequenom licensed the Oxford technology in 2005 and says it will likely sell the test for roughly $700 (U.S.).
Tests to determine the sex of a fetus, screen for Down syndrome and chromosomal abnormalities known as trisomies 13 and 18 will be the first on offer.
But CEO Harry Stylli said the company plans to develop screening tests for a range of other disorders, such as cystic fibrosis, sickle cell anemia and Tay-Sachs disease.
Yet even before the completion of large trials for Down syndrome, the company has been fielding calls from women across North America anxious to try the new screening test, he said.
“This [type of non-invasive test] has been viewed as the Holy Grail of testing,” Mr. Stylli said. “This is just a safer, more precise test. It is going to save women a great deal of anxiety.”
