Crozer-Chester Medical Center now offers pregnant women a new screening method for Down syndrome and Trisomy 18 that can detect cases earlier and more accurately. Conducted during the first trimester, the two-part test can provide parents and the obstetrician with valuable information about the pregnancy and screen for chromosomal and fetal abnormalities.
“Through the use of a simple finger stick and noninvasive ultrasound, we are now able to detect up to 90 percent of cases of Down syndrome during the first trimester of pregnancy,” says Anthony Sciscione, D.O., director of Maternal Fetal Medicine and chief of the Division of Obstetrics at Crozer-Chester Medical Center. “This is a higher detection rate than the current test offered during the second trimester.”
The new screening method involves two tests, both conducted between 11 and 13 weeks. In the first test, Nuchal Translucency, doctors use an ultrasound to measure the skin thickness at the back of the fetus’s neck. The second test is a blood test that measures certain proteins and hormones in the mother’s blood. In addition to these tests, patients are scheduled to meet with a genetic counselor to fully understand their risks and the procedure.
If the first trimester blood test and ultrasound indicate that the fetus has Down syndrome, the mother could opt to immediately undergo a conclusive diagnostic test called a Chorionic Villus Sampling (CVS) or an amniocentesis at 15 weeks gestation or later. However, both of these invasive procedures carry a small risk of miscarriage.
“The goal of first-trimester screening is to better determine who should have an amniocentesis or CVS,” Sciscione explains. “We are also hoping to reduce the rate of false positives for Down syndrome that exists with the traditional testing.”
Traditionally, testing for Down syndrome is done in the second trimester, between 15 and 21 weeks gestation. “A standard blood test is done to measure fetal and placental hormones to determine the likelihood of Down syndrome occurring in the fetus,” says Carolyn Hadley, M.D., a perinatologist at Crozer. “However, the accuracy rate is only 60 to 65 percent and many women must then resort to an amniocentesis at approximately 18 weeks for additional information.”
“This is yet one more example of Crozer’s commitment to providing our patients with the most up-to-date, state-of-the-art technology,” says Joel Noumoff, M.D., chairman of the Department of Obstetrics and Gynecology at Crozer-Chester Medical Center. “This test gives parents critical information about their child's birth experience.”
Down syndrome is one of the leading causes of mental retardation and serious birth defects. It occurs in about 1 in every 660 births, with that number increasing dramatically with the age of the expectant mother at the time of delivery. Any woman, regardless of her age, health or family history, can have a baby with Down syndrome.
The Nuchal Translucency test is not covered by insurance at this time. The fee for the procedure is $250. Most insurance companies are reimbursing for the cost of the blood tests, however.
For more information, ask your obstetrician or call the Antepartum Assessment Center at 1-877-94U-BABY (1-877-948-2229).