For years, many pregnant women have gone through a blood or ultrasound test that indicates a heightened risk of down syndrome, followed by a medical procedure to make a firm diagnosis by capturing DNA from the fetus. This medical procedure is usually the needle procedure called an amniocentesis, done almost four months or more into the pregnancy. Sometimes it's an earlier test called CVS, or chorionic villus sampling, which collects a bit of tissue from the placenta. Both pose a tiny but real chance for miscarriage.
But by this time next year there may be an alternative — one that offers accurate results as early as nine weeks into the pregnancy.
Companies are racing to market a more accurate blood test than those available now that could spare many women the need for an amnio or CVS. It would retrieve fetal DNA from the mother's bloodstream. And the answer could come before the pregnancy is obvious to others. For some women, that might mean abortion is a more tenable choice. For others it could be a mixed blessing. This definitely brings to the table the issue of whether this is a comfort or conflict.
Most cases are diagnosed after birth now, but if the blood test is widely adopted it could become chiefly a prenatal event.
A diagnosis before birth can pose a difficult challenge for couples as they decide whether to continue the pregnancy. It's not only about child-rearing, but also about what happens as the child grows into an older adult and may need care that the aging parents struggle to provide, says Dr. Mary Norton, a Stanford University professor of obstetrics and gynecology.
Currently, there are about 6,000 babies each year in the United States that are born with down syndrome, or about 1 in every 691 births.
Initially, doctors are expected to use the new blood test with women at risk for a Down syndrome pregnancy, such as those older than 35. A negative result would indicate a woman could skip the amnio or CVS; a positive result would suggest she get one done to be sure.
Eventually it might replace the routine screening tests offered to all pregnant women. Since the test sounds fewer false alarms than current tests, fewer women would be told they need the invasive follow-up procedures, experts say. And some suggest that with further fine-tuning, it could largely replace amnio and CVS. With no miscarriage risk, more women might be willing to take it, and so more women would find out they have a Down syndrome pregnancy.
Two California companies, Sequenom Inc. and Verinata Health Inc., hope to offer the test to doctors in the United States by next April. They say it could be done in the first trimester, with Sequenom aiming as early as 10 weeks, and Verinata as early as eight weeks. Results would be available 7 to 10 days later. None of the companies would discuss its cost.
Since the new blood test could deliver an answer so early — before a pregnancy is showing or the baby is kicking — it might make getting an abortion easier, several observers said. Women haven't bonded so much, and "they wouldn't have to explain to as many people," said Christie Brooks, who moderates an online support group for women who've gotten abortions for medical reasons.
Some say the blood test could thrust some women into a choice they didn't ask to make.
If these tests are someday replaced by the new blood test, many women may be told out of the blue not simply that they're at risk, but that in fact their baby almost surely has Down syndrome, says Hank Greely, a Stanford University law professor.
"They're going to jump directly to the final answer, which is not necessarily something they wanted to get," Greely said. So the new test poses a challenge to the medical establishment about how to assure that women get adequate counseling to make an informed choice, he said.
I hope you read this post carefully, because if this new test takes over the current test next year, it will be a great blessing to some women, and a tremendous ethical dilemma for others. It will most certainty cause a drastic change in the pregnancy of those 6,000 mothers every year.
