Screening For Down Syndrome
Screening For Down Syndrome: Nuchal translucency testing. This test, performed between 11 and 14 weeks of pregnancy, uses ultrasound to measure the clear space in the folds of tissue behind a developing baby's neck. (Babies with DS and other chromosomal abnormalities tend to accumulate fluid there, making the space appear larger.)
This measurement, taken together with the mother's age and the baby's gestational age, can be used to calculate the odds that the baby has DS. Nuchal translucency testing is usually performed along with a maternal blood test.
The triple screen or quadruple screen (also called the multiple marker test). These tests measure the quantities of normal substances in the mother's blood. As the names imply, triple screen tests for three markers and quadruple screen includes one additional marker and is more accurate. These tests are typically offered between 15 and 18 weeks of pregnancy. Integrated screen.
This uses results from first trimester screening tests (with or without nuchal translucency) and blood tests with second trimester quad screen to come up with the most accurate screening results. A genetic ultrasound. A detailed ultrasound is often performed at 18 to 20 weeks in conjunction with the blood tests, and it checks the fetus for some of the physical traits abnormalities associated with Down syndrome.
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