First Trimester
Down Syndrome Screen
Formal name: First Trimester Screen [Pregnancy-associated plasma protein-A (PAPP-A), human chorionic gonadotropin (hCG) as either free beta subunit or total hCG, and nuchal translucency ultrasound]
Related tests: Triple/Quad Screen; total hCG
At a Glance
Why Get Tested?
To assess the risk of carrying a fetus with chromosomal abnormalities, such as Down syndrome and trisomy 18
When to Get Tested?
Usually between 10 weeks, 4 days and 13 weeks, 6 days of pregnancy
Sample Required?
A blood sample drawn from a vein in the arm and a special ultrasound
Test Preparation Needed?
You may be instructed to have a full bladder when having the nuchal translucency ultrasound performed.
