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First Trimester
Down Syndrome Screen

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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 a fetus having a chromosomal abnormality, such as Down syndrome (trisomy 21) or Edwards syndrome (trisomy 18)

When to Get Tested?

Usually between 11 and 14 weeks of pregnancy

Sample Required?

A blood sample drawn from a vein in your arm or a blood spot collected on special paper from a finger stick; a nuchal translucency requires a special ultrasound exam.

Test Preparation Needed?

You may be instructed to have a full bladder when having the nuchal translucency ultrasound performed.