During pregnancy, there is so much to think about. Is it a boy or a girl? What hospital, what obstetrician will deliver your baby? And of course, is the baby healthy? Over the past few years, new testing has become available to answer that question. Testing for nuchal translucency and first trimester testing can help determine if the baby has Down syndrome or certain other birth defects. While no testing is 100 percent accurate and no amount of testing can determine all birth defects, it now possible to help answer the question; is my baby healthy?
Kypros Nicholaides developed nuchal translucency in England, and large-scale studies have been completed in the U.S. including at Eastern Virginia Medical School in Norfolk, Virginia.
Nuchal translucency testing starts with a blood test on the pregnant woman. An ultrasound in the third month of pregnancy measures the clear space at the back of the developing baby’s neck. A second blood test is done in the fourth month of pregnancy. All this information is analyzed. A risk estimate is determined. In other words the chance the developing baby has one of these birth defects is calculated. Women are then counseled to help them decide what all the testing means.
Pregnant women who are 35 years old have a 1 in 270 chance of delivering a child with Down syndrome. Women who are 35 years or older are routinely offered amniocentesis to test for Down syndrome. Now an alternative exists. This process of testing for nuchal translucency and maternal blood can give the reassurance that the developing baby is all right and eliminate the need for amniocentesis.
The NT testing can also be offered to all pregnant women to help determine if their baby has Down syndrome or certain other birth defects. The advantages of the NT tests include a relatively accurate test for chromosomal problems without the risk of miscarriage associated with other more invasive tests like amniocentesis or chorionic villus sampling or CVS. The most common birth defects that NT testing tests for include Down syndrome or Trisomy 21. Down Syndrome is a genetic disorder associated with mental retardation and birth defects affecting the developing baby’s heart and kidney among others. Trisomy 18 can also be detected by NT testing. This genetic disorder is associated with multiple birth defects or infants die shortly after birth. This disorder is rare, occurring 1 in 8000 births.
Pregnancy is a special time in a woman’s life. Prenatal testing can help pregnant women answer the question, is my baby healthy? The testing can be completed in the first half of pregnancy (before 20 weeks). While 3-5 percent of pregnancies are associated with a birth defect, many can be determined prenatally. Other noninvasive tests are on the horizon. Various medical centers are exploring techniques to detect fetal birth defects with a simple blood test. One such test looks for the small amounts of fetal DNA that leaks into the maternal circulation.
In the future it is hoped that all genetic birth defects could be detected by simply drawing a blood sample from the pregnant woman. Ask your health care provider to help you decide if testing is right for you.
Dr. Hardy is a solo physician with locations in Chesapeake and Va. Beach. Please call 463-1234 or visit www.atlanticobgyn.com.