Q: What is nuchal translucency screening?
A: A test usually done between the eleventh and fourteenth week of pregnancy. The test involves an ultrasound of the back of the baby's neck. This area has a clear space, which is known as the nuchal fold.
Q: What are you testing for?
A: To determine your baby's risk of having certain birth defects, most notably Down Syndrome and other chromosomal abnormalities. In babies with Down Syndrome, this clear space tends to be larger than in healthy babies.
Q: Who should take this test?
A: This test is most often done on mothers who are considered at increased risk due to advanced maternal age.
NT screening is available for any pregnant woman. It can be especially helpful for older moms-to-be who are at greater risk for having a baby with a chromosomal disorder and who may be hesitant about more invasive genetic testing, like CVS and amniocentesis, because of the increased risk of miscarriage associated with them. Other likely candidates for NT screening are mothers with a history of problems in prior pregnancies or a family history of chromosomal disorders.
If you are offered this test, it's important to understand that this is a screening test. It does not give a definitive diagnosis, but shows that a baby may be at increased risk of having certain abnormalities. A combination of an ultrasound and a blood test are used to determine this risk.
If the test shows that your baby is at an increased risk for Down's Syndrome, this doesn't mean the baby definitely has it. Further testing is needed to offer a definitive diagnosis. An amniocentesis or chorionic villus sampling can be done to give a true diagnosis. A level two ultrasound can also be done, if you are uncomfortable with the risk of the amniocentesis.