Double Marker - First Trimester

Pregnancy

Report in 48Hrs

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No Fasting Required

Details

Non-invasive prenatal blood test done during the first trimester of pregnancy to assess the risk of chromosomal abnormalities in the fetus

₹699₹2,200

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Double Marker - First Trimester Test Information Guide

Why is it done?
- The Double Marker test is a prenatal screening test that measures two biochemical markers in maternal blood to assess the risk of chromosomal abnormalities in the fetus, primarily Down syndrome (Trisomy 21) and Edwards syndrome (Trisomy 18)
- Performed during the first trimester (between 11-14 weeks of gestation) in combination with nuchal translucency ultrasound measurement
- Used as a non-invasive screening tool to identify pregnancies at higher risk for chromosomal abnormalities
- Recommended for all pregnant women as part of routine first trimester screening
- Helps guide counseling and decisions regarding further diagnostic testing such as amniocentesis or chorionic villus sampling (CVS)
Normal Range
- PAPP-A (Pregnancy-Associated Plasma Protein A): Normal Range: 0.5 - 2.5 MoM (Multiples of the Median) Units: mIU/mL or IU/L Higher levels typically indicate lower risk; lower levels may suggest increased risk for Down syndrome
- Free Beta-hCG (Human Chorionic Gonadotropin): Normal Range: 0.5 - 2.5 MoM Units: mIU/mL or ng/mL Higher levels may indicate increased risk for Down syndrome; lower levels may suggest Edwards syndrome
- Overall Risk Assessment: Low Risk: Calculated risk less than 1 in 250-300 Intermediate/Borderline Risk: Risk between 1 in 250-1 in 50 High Risk: Calculated risk greater than 1 in 50 Interpretation is always combined with maternal age and nuchal translucency measurement
- Results are expressed as MoM to account for normal variation in marker levels throughout the first trimester
Interpretation
- Low PAPP-A + Elevated Free Beta-hCG Pattern: Suggestive of increased risk for Down syndrome (Trisomy 21) Sensitivity for detection: 60-70%
- Low PAPP-A + Low Free Beta-hCG Pattern: Suggestive of increased risk for Edwards syndrome (Trisomy 18) May also indicate other chromosomal abnormalities
- High PAPP-A + Normal Free Beta-hCG: Generally indicates lower risk for chromosomal abnormalities
- Factors Affecting Interpretation: Gestational age accuracy: ±3-5 days Maternal age: Older age increases baseline risk Maternal weight: May affect marker levels Maternal race/ethnicity: Different baseline values for different populations Type of pregnancy: Multiple gestations affect interpretation Diabetes (gestational or pre-existing): May alter marker levels Smoking status: Some studies show effects on markers
- Clinical Significance: Results are probabilistic, not diagnostic When combined with nuchal translucency ultrasound and maternal age, detection rates improve to 85-90% Combined screening is more accurate than individual marker alone Abnormal results warrant further discussion regarding diagnostic options
Associated Organs
- Primary Organ System Involved: Reproductive system (placenta and fetus) Maternal endocrine system (hormone production)
- Chromosomal Abnormalities Detected: Trisomy 21 (Down syndrome): Most common autosomal trisomy Trisomy 18 (Edwards syndrome): Severe fetal abnormality Trisomy 13 (Patau syndrome): May be detected but less reliably Other chromosomal aneuploidies
- Associated Medical Conditions in Affected Fetuses: Down syndrome: Intellectual disability, congenital heart defects, GI abnormalities Edwards syndrome: Severe developmental abnormalities, multiple organ involvement, usually lethal Patau syndrome: Severe malformations, often perinatally lethal
- Marker Origins: PAPP-A: Produced by placental tissue (primarily syncytiotrophoblast) Free Beta-hCG: Produced by trophoblastic tissue of the placenta
- Potential Complications: Psychological anxiety from abnormal screening results Unnecessary invasive testing (amniocentesis/CVS) if results are false positive Risk of pregnancy loss (0.1-0.3%) if diagnostic procedures are performed Maternal-fetal complications if pregnancy continues with affected fetus
Follow-up Tests
- If Results are Abnormal or High-Risk: Detailed ultrasound scan: To assess fetal anatomy and soft markers for chromosomal abnormalities Chorionic Villus Sampling (CVS): Diagnostic test performed at 11-14 weeks Amniocentesis: Diagnostic test performed at 15+ weeks
- Second Trimester Options: Quadruple marker test (between 15-22 weeks): Includes AFP, hCG, uE3, and inhibin A Integrated screening: Combines first trimester and second trimester results for improved accuracy
- Non-Invasive Prenatal Testing (NIPT): Cell-free fetal DNA testing: Alternative or confirmatory screening method Can be performed from 10 weeks gestation Higher detection rates and lower false positive rates than serum screening
- Complementary Tests: Maternal serum alpha-fetoprotein (AFP): For neural tube defects Ultrasound assessment of nuchal translucency: Should accompany this test Fetal echocardiography: If cardiac defects suspected Karyotyping: Definitive test following diagnostic procedures
- Monitoring and Follow-Up Frequency: If low-risk: Standard prenatal care and routine second trimester ultrasound If high-risk: Genetic counseling within 1-2 weeks If diagnostic testing declined: Enhanced ultrasound screening at 18-22 weeks If confirmed abnormality: Specialized prenatal care and pediatric subspecialty consultation
- If Results are False Positive: Reassurance and emotional support Standard pregnancy follow-up Opportunity to discuss implications with genetic counselor
Fasting Required?
- Fasting Status: NO - Fasting is NOT required for this test
- Blood Draw Requirements: Standard venipuncture for serum collection Blood sample can be collected at any time of day No dietary restrictions required Patient can eat, drink, and take medications as normal
- Timing Requirements: Blood sample must be collected between 11-14 weeks of gestation Accurate dating of pregnancy is essential (typically by first trimester ultrasound) Sample should be collected ±3-5 days of the calculated date for accurate interpretation
- Special Preparation Instructions: Attend nuchal translucency ultrasound appointment during same visit or within 1-2 weeks Bring confirmation of gestational age (LMP dating or prior ultrasound) Inform provider of maternal age and any family history of genetic abnormalities Discuss pregnancy details: singleton vs multiple gestation, maternal weight, race/ethnicity
- Medications: No medications need to be withheld Continue all regular prenatal medications and supplements Prenatal vitamins do not interfere with test results Aspirin and other common medications do not affect results
- Sample Handling: Blood collected in serum separator tube (SST) or plasma tube depending on laboratory protocol Sample should be processed and refrigerated promptly Transport to laboratory within specified timeframe (usually 24 hours) Results typically available within 3-7 business days

How our test process works!