First Trimester Quadruple Marker Test

The quadruple marker (quad) is a second‑trimester screen (about 15–20 weeks), not a first‑trimester test. Costs vary: it's usually free under public healthcare systems. In private settings, typical ranges are roughly ₹700–₹3,000 in India and about US$50–$250 in the US, though insurance can greatly alter out‑of‑pocket expense. Confirm exact pricing with your provider.

Quad screen results are reported as multiples of the median (MoM). Each analyte is generally considered within the normal range when roughly 0.5–2.0 MoM. Values outside this range may alter risk estimates for chromosomal conditions or neural-tube defects. Interpretation depends on gestational age, maternal factors and lab-specific adjustments; abnormal results usually prompt further diagnostic testing.

The best time to do a quadruple marker screen is between 15 and 20 weeks of pregnancy, with optimal accuracy around 16–18 weeks. Accurate gestational dating (usually by early ultrasound) is essential because results depend on precise pregnancy age. Testing before 15 or after 20 weeks reduces reliability; discuss any abnormal results with your clinician for follow-up testing or diagnostic options.

You shouldn’t panic: a positive quadruple marker indicates increased risk for certain chromosomal conditions or neural tube defects, but it’s a screening test—not diagnostic. Many positives are false alarms. Next steps: confirm dating, get a detailed ultrasound, consider cell‑free DNA (NIPT) for clearer risk assessment, and discuss diagnostic testing (CVS/amniocentesis) and genetic counselling.

The quad screen measures four maternal blood markers (AFP, hCG, estriol, inhibin A) to estimate a fetus’s risk of Down syndrome. It is a screening test—not diagnostic—so results can be false positive or negative. Performed in the second trimester (about 15–20 weeks), an abnormal screen prompts confirmatory testing such as noninvasive prenatal testing, chorionic villus sampling, or amniocentesis.

A positive quadruple screen indicates increased risk, not a diagnosis. Next steps: discuss results with your clinician and a genetic counselor, get a detailed ultrasound, and consider noninvasive prenatal testing (cfDNA) for more accurate risk assessment. Definitive diagnosis requires invasive testing—chorionic villus sampling (first trimester) or amniocentesis (second trimester)—with counseling about benefits and small miscarriage risks.