By Dave Andrusko
A two-part series written this week by veteran Associated Press science reporter Malcolm Ritter wrestled with the impact of a new blood test that will make it possible for women to know as early as nine weeks into their pregnancy whether their baby has Down syndrome. We will talk about it briefly today and in more depth tomorrow.
“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,” Ritter writes. “A negative result would indicate a woman could skip the amniocentesis or CVS [chorionic villus sampling]; a positive result would suggest she get one done to be sure.”
Amniocentesis and CVS carry a small risk of causing a miscarriage. “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,” he explains. Using current techniques, prenatal diagnoses are estimated to result in the deaths of 9 out of ten of these babies.
Ritter interviewed Dr. Brian Skotko, a Down syndrome specialist at Children’s Hospital Boston. Dr. Skotko, who has written a research paper for doctors on how to deliver a diagnosis, said “the vast majority of people with Down syndrome and families affirm that their contributions to their communities are significant, and their lives are very valuable.”
But the availability of prenatal screening has already cost many lives. Skoto “cites one study that concludes the number of Down syndrome births in the nation dropped 11 percent between 1989 and 2006, a time when it would otherwise be expected to rise 42 percent,” according to Ritter.