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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]

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.