Re: What happens during nuchal translucency screening?
A nuchal translucency screening is basically a (totally painless!) special ultrasound that tests primarily for Down syndrome. Your doc will lather your belly with gel and rub a transducer over it, which emits sound waves that then become electrical signals, and voilà! You’ll see baby’s picture on a nearby screen. While you're absorbed with that, your doc will examine the back of baby’s neck. If this area is thicker than normal, it can be an early warning sign of Down syndrome, trisomy 18 (another genetic disorder) and other related birth defects.
Make an appointment with your doctor sometime between 10 and 14 weeks for this test. You'll probably undergo a combined screening, including a serum test to check your blood. Together, these two tests determine whether baby has a genetic defect. Remember -- though a nuchal translucency test might show increased thickness in baby’s neck, your blood test results could rule out Downsyndrome. In this scenario, there is the possibility of a slight heart defect, and your doctor will most likely run further tests on your baby’s heart.
American College of Obstetrics and Gynecologists. Your pregnancy and birth. 4th ed. Washington, DC: ACOG; 2005.