Expectant mothers will soon be able to know quite a bit more about the unborn child they re carrying maybe more than they need to know. New gene tests that go far beyond traditional chromosomal evaluation in looking for genetic abnormalities are on the horizon. Genetic microarray analysis promises to detect everything from autism to club foot, according to a report in the New England Journal of Medicine.
Genetic analysis of whatever precision are done on fetal cells obtained through chorionic villus sampling cells obtained through amniocentesis, a procedure in which a specialized physician inserts a long, skinny needles into the placenta and obtains cell samples. This test is generally done between the 15th and 18th weeks of pregnancy, and has a small but real risk of complications.
In the current study, the new gene tests (called microarrays) found abnormalities in the cells of 6 percent of fetuses declared normal by conventional chromosomal evaluation, which is done with a microscope, according to the study of 4,400 pregnant women. They both rely on fetal cells extracted during an amnio, but the chromosomal microarrays are scanned with gene chips rather than examined under a microscope.
ACSH staff is a bit uneasy about the widespread use of fetal gene testing. A significant amount of the time you can get an abnormal result without a clinical illness, ACSH s Dr. Gilbert Ross says. Many people may have gene abnormalities that they never even realize, he says. I fear that many women would be panic-stricken by news of what is a minor abnormality or nothing at all from this test. On the other hand, any anxieties can be dampened by a full discussion of possible outcomes and plans for dealing with them, among the doctor, mom-to-be, and her significant other.
