Test guide
Double Marker Test
A blood test done near the end of the first trimester of pregnancy to screen for common chromosomal defects. This test screens for blood levels of both free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A) and can detect trisomies of chromosomes 21 (Down's syndrome), chromosome 18 (Edward's syndrome), and chromosome 13 (Patau's syndrome).
What it is for
Source: National Cancer Institute, NCI Thesaurus 26.09d, C222234. Unmodified NCI definition, CC BY 4.0. Source identity and classification checked automatically on 2026-10-20.
Limitations
Terminology reference for a laboratory procedure. The source definition does not establish routine clinical availability, validated specimen types, reference intervals, product authorization or suitability for an individual. Consult the performing laboratory for its validated method and interpretation.
Also known as
- Double Marker Test
- Double Screen
Reviewed products
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