Double Marker Test is a prenatal screening test conducted to assess the risk of genetic disorders in a developing fetus. The test is usually performed between the 11th and 14th weeks of pregnancy and involves a combination of two blood tests – nuchal translucency (NT) scan and blood tests that detect two markers – Pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin (HCG). The test provides an estimated risk for chromosomal abnormalities such as Down syndrome, trisomy 18, and trisomy 13.
Benefits of Double Marker Test:
- Early Detection: The Double Marker Test is performed in the early stages of pregnancy, providing an early indication of any potential genetic disorders in the fetus.
- Non-Invasive: Unlike invasive tests like amniocentesis and chorionic villus sampling, the Double Marker Test is a non-invasive test that poses no risk to the mother or the fetus.
- Accurate Results: The Double Marker Test has a high accuracy rate in detecting chromosomal abnormalities. When combined with an NT scan, the test has a detection rate of over 90% for Down syndrome.
- Cost-effective: The Double Marker Test is a cost-effective alternative to invasive tests and provides a safe and convenient option for expectant mothers.
Results of the Double Marker Test:
- Low-risk results: If the results of the Double Marker Test are low-risk, it indicates that there is a low probability of chromosomal abnormalities in the fetus. This result provides reassurance to the expectant mother and allows her to continue the pregnancy without any additional tests.
- High-risk results: If the results of the Double Marker Test are high-risk, it indicates that there may be a higher probability of chromosomal abnormalities in the fetus. In such cases, further invasive tests like amniocentesis or chorionic villus sampling may be recommended to confirm the results.
It is important to note that a high-risk result does not necessarily mean that the fetus has a chromosomal abnormality. It only indicates a higher probability and further tests are required to confirm the results.
Double Marker Test Risk Factors:
The Double Marker Test is a non-invasive prenatal screening test, and as such, it does not pose any direct risk to the mother or the fetus. However, there are some associated risks that expectant mothers should be aware of:
- False Positive Results: Although the Double Marker Test has a high accuracy rate, there is a small chance of a false positive result. A false positive result indicates a higher risk of chromosomal abnormalities when, in fact, there is none.
- False Negative Results: Similarly, there is a small chance of a false negative result, which indicates a low risk of chromosomal abnormalities when, in fact, there is a higher risk.
- Anxiety and Stress: Receiving a high-risk result can cause anxiety and stress for the expectant mother and her family. It is important for expectant mothers to understand the results and seek appropriate follow-up tests if necessary.
- Unnecessary Invasive Tests: In some cases, a high-risk result from the Double Marker Test may lead to further invasive tests like amniocentesis or chorionic villus sampling. These tests carry a small risk of miscarriage and should only be performed if necessary.
The Double Marker Test is a non-invasive, cost-effective, and accurate option for prenatal screening. The test provides an early indication of any potential genetic disorders in the fetus and allows expectant mothers to make informed decisions about their pregnancy. It is important to understand the results of the test and seek appropriate follow-up tests if necessary. Expectant mothers should consult with their healthcare provider to determine if the Double Marker Test is appropriate for them.