<div><div>A <strong>Double Marker Test</strong> is a prenatal screening test typically conducted during the first trimester of pregnancy (between 10 and 14 weeks). It helps assess the risk of chromosomal abnormalities in the fetus, such as <strong>Down syndrome (Trisomy 21)</strong>, <strong>Edward syndrome (Trisomy 18)</strong>, or other genetic conditions.</div><h3>How It Works:</h3><ol><li><div><strong>Blood Test</strong>: A sample of the mother’s blood is taken to measure the levels of two key markers:</div><ul><li><strong>Free Beta hCG</strong>: A hormone produced during pregnancy.</li><li><strong>PAPP-A (Pregnancy-Associated Plasma Protein-A)</strong>: A protein that helps with placental development.</li></ul></li><li><div><strong>Ultrasound (Nuchal Translucency Test)</strong>:</div><ul><li>Often combined with the Double Marker Test.</li><li>Measures the thickness of the fluid-filled space at the back of the fetus's neck (nuchal translucency).</li></ul></li><li><div><strong>Risk Calculation</strong>:</div><ul><li>Results are combined with maternal factors (age, weight, gestational age, etc.) to determine the risk score.</li></ul></li></ol><h3>Purpose:</h3><ul><li>To identify the <strong>likelihood</strong> of chromosomal abnormalities but not confirm them.</li><li>Low-risk results suggest normal chromosomal development, while high-risk results may prompt further diagnostic tests like <strong>amniocentesis</strong> or <strong>chorionic villus sampling (CVS)</strong>.</li></ul><h3>Benefits:</h3><ul><li>Non-invasive and safe for both mother and baby.</li><li>Helps parents make informed decisions and prepare for potential outcomes.</li></ul><h3>Limitations:</h3><ul><li>It's a <strong>screening</strong> test, not a diagnostic test, so it only indicates the level of risk.</li></ul><div><h3><strong>Key Differences</strong>:</h3><table><thead><tr><th><strong>Feature</strong></th><th><strong>NIPT</strong></th><th><strong>Double/Triple Marker Tests</strong></th></tr></thead><tbody><tr><td><strong>Timing</strong></td><td>From 10 weeks onward</td><td>10–14 weeks (Double), 15–20 weeks (Triple)</td></tr><tr><td><strong>Method</strong></td><td>Analyzes fetal DNA in maternal blood</td><td>Measures hormone/protein levels in maternal blood</td></tr><tr><td><strong>Conditions Detected</strong></td><td>Chromosomal abnormalities</td><td>Chromosomal abnormalities (+ neural tube defects for Triple)</td></tr><tr><td><strong>Accuracy</strong></td><td>High (>99%)</td><td>Moderate; provides a risk score</td></tr><tr><td><strong>Invasiveness</strong></td><td>Non-invasive</td><td>Non-invasive</td></tr><tr><td><strong>Cost</strong></td><td>Expensive</td><td>More affordable</td></tr><tr><td><strong>Neural Tube Defects</strong></td><td>Not detected</td><td>Detected by Triple Marker Test</td></tr></tbody></table></div></div> <div><div>A <strong>Double Marker Test</strong> is a prenatal screening test typically conducted during the first trimester of pregnancy (between 10 and 14 weeks). It helps assess the risk of chromosomal abnormalities in the fetus, such as <strong>Down syndrome (Trisomy 21)</strong>, <strong>Edward syndrome (Trisomy 18)</strong>, or other genetic conditions.</div><h3>How It Works:</h3><ol><li><div><strong>Blood Test</strong>: A sample of the mother’s blood is taken to measure the levels of two key markers:</div><ul><li><strong>Free Beta hCG</strong>: A hormone produced during pregnancy.</li><li><strong>PAPP-A (Pregnancy-Associated Plasma Protein-A)</strong>: A protein that helps with placental development.</li></ul></li><li><div><strong>Ultrasound (Nuchal Translucency Test)</strong>:</div><ul><li>Often combined with the Double Marker Test.</li><li>Measures the thickness of the fluid-filled space at the back of the fetus's neck (nuchal translucency).</li></ul></li><li><div><strong>Risk Calculation</strong>:</div><ul><li>Results are combined with maternal factors (age, weight, gestational age, etc.) to determine the risk score.</li></ul></li></ol><h3>Purpose:</h3><ul><li>To identify the <strong>likelihood</strong> of chromosomal abnormalities but not confirm them.</li><li>Low-risk results suggest normal chromosomal development, while high-risk results may prompt further diagnostic tests like <strong>amniocentesis</strong> or <strong>chorionic villus sampling (CVS)</strong>.</li></ul><h3>Benefits:</h3><ul><li>Non-invasive and safe for both mother and baby.</li><li>Helps parents make informed decisions and prepare for potential outcomes.</li></ul><h3>Limitations:</h3><ul><li>It's a <strong>screening</strong> test, not a diagnostic test, so it only indicates the level of risk.</li></ul><div><br></div></div><div><h3><strong>Key Differences</strong>:</h3><table><thead><tr><th><strong>Feature</strong></th><th><strong>NIPT</strong></th><th><strong>Double/Triple Marker Tests</strong></th></tr></thead><tbody><tr><td><strong>Timing</strong></td><td>From 10 weeks onward</td><td>10–14 weeks (Double), 15–20 weeks (Triple)</td></tr><tr><td><strong>Method</strong></td><td>Analyzes fetal DNA in maternal blood</td><td>Measures hormone/protein levels in maternal blood</td></tr><tr><td><strong>Conditions Detected</strong></td><td>Chromosomal abnormalities</td><td>Chromosomal abnormalities (+ neural tube defects for Triple)</td></tr><tr><td><strong>Accuracy</strong></td><td>High (>99%)</td><td>Moderate; provides a risk score</td></tr><tr><td><strong>Invasiveness</strong></td><td>Non-invasive</td><td>Non-invasive</td></tr><tr><td><strong>Cost</strong></td><td>Expensive</td><td>More affordable</td></tr><tr><td><strong>Neural Tube Defects</strong></td><td>Not detected</td><td>Detected by Triple Marker Test</td></tr></tbody></table></div>
