Prenatal Screening: Double Test

Double Test Screening Solution

1. Overview of the Double Test

The Double Test is a non-invasive prenatal screening method typically performed during the first trimester of pregnancy (from 11 weeks to 13 weeks and 6 days of gestation). The test analyzes maternal serum to quantitatively measure two biochemical markers: free β-hCG (the free beta subunit of human chorionic gonadotropin) and PAPP-A (Pregnancy-Associated Plasma Protein A).

When combined with nuchal translucency ultrasound measurements and clinical information such as maternal age, these biochemical results help assess the risk of fetal chromosomal abnormalities. The most commonly screened conditions include Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18), and Patau syndrome (Trisomy 13).

2. Revvity’s Solution for Double Test Screening

Free hCGß

• Product name: DELFIA® Free hCGß
• Product code: A097-101
• Manufacturer: Wallac Oy – Finland
• Packaging: 96 tests
• Application:

This kit is used for the quantitative measurement of free β-subunit of human chorionic gonadotropin (free hCGß) in maternal serum.

• Assay Principle:

The DELFIA® Free hCGß assay is a two-site solid-phase time-resolved fluorescence immunoassay using a direct sandwich technique. Two monoclonal antibodies (mouse-derived) are directed against two distinct epitopes on the free hCGß molecule.

PAPP-A

• Product name: DELFIA® PAPP-A
• Product code: A098-201
• Manufacturer: Wallac Oy – Finland
• Packaging: 96 tests
• Application:

This kit is used for the quantitative measurement of Pregnancy-Associated Plasma Protein A (PAPP-A) in maternal serum.

• Assay Principle:

The DELFIA® PAPP-A assay is a two-site solid-phase time-resolved fluorescence immunoassay using an indirect sandwich technique. Two mouse-derived monoclonal antibodies are directed against two distinct epitopes on the PAPP-A/proMBP complex.

3. Required Equipment and Software

• VICTOR™2 D fluorometer
• DELFIA™ Trio
• DELFIA™ Plateshake
• LifeCycle™ prenatal screening software