Researchers Study Faster Screening Method For Down Syndrome
New York, NY, November 18, 1999 Columbia Presbyterian Center researchers join 10 other major medical centers to conduct a nationwide study of screening tests that promise to improve prenatal detection of Down syndrome. The study, called The FASTER Trial (First And Second Trimester Evaluation of Risk), is backed by a $10 million three-year grant from the National Institutes of Health and the National Institute of Child Health and Human Development. FASTER tests include nuchal translucency, an ultrasound measurement of the thickness of the skin on the back of the fetal neck, and analysis of serum markers, specific substances in the maternal blood. Increased neck thickness and abnormal maternal blood markers can indicate a high risk of Down syndrome, thus providing earlier clues to one of the most troubling questions a woman faces during pregnancy.
Credit: Columbia University Caption: Ultrasound imaging can reveal the thickness of the nuchal fold, the skin at the back of the neck of a fetus, which can be used to screen for Down syndrome. The nuchal fold in the image at left suggests that the fetus may have Down syndrome. The mother would need an amniocentesis or chorionic villus sampling for a definitive diagnosis. Click here to download image FASTER is led by Mary D'Alton, M.D., professor of obstetrics & gynecology at Columbia University College of Physicians & Surgeons and director of maternal - fetal medicine, Sloane Hospital for Women at the Columbia Presbyterian Center of the NewYork-Presbyterian Hospital, and co-principal investigator Fergal Malone, M.D., assistant professor of obstetrics & gynecology at Columbia University College of Physicians & Surgeons and director of perinatal research at Sloane Hospital for Women. The researchers are are currently recruiting study participants. The other participating researchers in New York are Dr. Irwin Merkatz of Montefiore Medical Center, the University Hospital for the Albert Einstein College of Medicine; Dr. Richard Berkowitz, Mount Sinai Medical Center; Dr. Ilan Timor-Tritsch and Dr. Michael Paidas of NYU Medical Center.
"It is crucial that we carefully evaluate this new procedure now, as it is already creeping into clinical practice. The objective of FASTER is to find the safest and most effective screening tests for Down syndrome," says Dr. D'Alton. "Initial studies indicate that both nuchal translucency and serum markers could play an earlier and important role in prenatal diagnosis of Down syndrome and may help better identify which women should go on to have an invasive diagnostic test, such as amniocentesis."
Down syndrome is one of the most common causes of serious birth defects, occurring in approximately one in 660 live births. Amniocentesis and chorionic villus sampling (CVS) can determine definitively if the fetus has Down syndrome. But both tests on rare occasions can cause miscarriage. Typically, many women will use the results of blood tests, such as the "AFP test" or "triple screen," to determine whether they are more likely to have a baby with Down Syndrome. The tests help patients decide whether to undergo amniocentesis. The "triple screen," which analyzes three markers in a woman's blood, helps identify 60 percent to 65 percent of fetuses with Down syndrome. It is performed in the second trimester, with final results from amniocentesis usually not available until the 18th week of pregnancy or later.
"It is very difficult for families to be almost halfway through the pregnancy before finding out if their baby has Down syndrome," says Dr. D'Alton.
The FASTER Trial investigators are studying earlier and perhaps more accurate screening tests for Down syndrome. Preliminary studies have suggested that the nuchal translucency (NT) test can detect as many as 80 percent of the fetuses with Down syndrome. The NT test is performed early in pregnancy, at 10-14 weeks. This test may also identify fetuses at increased risk for other birth defects, especially problems with the heart. Researchers will precisely document the effectiveness of the NT test, in combination with maternal blood markers, at detecting fetuses with Down syndrome, and compare this new first trimester testing with currently available second-trimester screening tests.
FASTER researchers are recruiting 60,000 pregnant women at medical centers throughout the United States. At 10-14 weeks of pregnancy, women will get the NT test and the two new blood test, then at 15-16 weeks they will have the standard "triple screen" together with analysis of another new blood marker. Women who are found to be at risk for Down syndrome on either screening method will be given genetic counseling and offered the option of amniocentesis.
"The results of the FASTER Trial will have a profound impact on the way pregnant women are screened for Down syndrome. If we can make the diagnosis earlier it will be better for pregnant women everywhere," says Dr. Malone.
Additional participating centers are The Mount Sinai Hospital and NYU Hospitals Center of Mount Sinai NYU Health; Montefiore Medical Center; Women and Infants' Hospital, Rhode Island; William Beaumont Hospital, Michigan; Intermountain HealthCare System, Utah; University of Texas Medical Branch, Galveston; University of Colorado Health Sciences Center, Denver; Swedish Medical Center, Seattle; and New England Medical Center, Boston. For more information on the study, please call 212-305 FAST.