Double Marker Test: Everything You Need to Know for a Healthy Pregnancy

The journey of pregnancy is an exciting and transformative time for women. It is essential to prioritize the health and well-being of both the mother and the baby throughout this period. One crucial aspect of prenatal care is the double marker test, which plays a significant role in assessing the risk of certain chromosomal abnormalities.

In this article, we will delve into the meaning, necessity, procedure, and analysis of the double marker test in pregnancy. By understanding this test and its results, expectant mothers can make informed decisions for a healthy pregnancy.

Double Marker Test Meaning: What is Double Marker Test?

The double marker test means a blood test performed during pregnancy to evaluate the risk of chromosomal abnormalities, particularly Down syndrome (Trisomy 21) and Edwards syndrome (Trisomy 18). It is also known as the dual marker test.

This test combines two specific markers in the mother's blood - human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein-A (PAPP-A). The levels of these markers, along with other factors like maternal age and gestational age, help determine the probability of chromosomal abnormalities in the fetus.

Is it Necessary to Get Double Marker Test in Pregnancy?

While the decision to undergo the double marker blood test in pregnancy is entirely personal. It is highly recommended by healthcare professionals, especially for women who are at increased risk due to advanced maternal age or a previous history of chromosomal abnormalities.

The test provides valuable information about the likelihood of certain genetic conditions, allowing expectant parents to make informed decisions regarding further diagnostic tests or interventions. Although the test cannot diagnose chromosomal abnormalities with certainty, it helps identify those at higher risk and facilitates appropriate management and counseling.

Why Double Marker Test is Done?

The primary purpose of the double marker test during pregnancy is to assess the risk of chromosomal abnormalities in the fetus. By analyzing the levels of hCG and PAPP-A in the mother's blood, the test can provide an estimate of the probability of Down syndrome and Edwards syndrome.

Early detection of these conditions enables healthcare providers to offer comprehensive counseling, discuss available options, and plan for appropriate interventions if necessary. The test also helps alleviate anxiety and uncertainty for expectant parents, allowing them to prepare emotionally and practically for the arrival of their baby.

You may also like: Noninvasive Prenatal Testing (NIPT) | All You Need To Know

Double Marker Test Time

The double marker test is typically performed between the 10th and 14th weeks of pregnancy. This specific time frame is chosen because the levels of hCG and PAPP-A are known to be stable during this period, providing reliable results.

It is essential to note that timing may vary slightly depending on individual healthcare providers and their protocols. Therefore, it is crucial for expectant mothers to consult with their obstetrician or prenatal care provider to determine the most appropriate time for the test based on their specific circumstances.

You may also like: What Are the Common Tests You Will Have During Your Pregnancy?

How Double Marker Test is Done?

The double marker test during pregnancy is a simple and non-invasive blood test that can be performed at any reputable laboratory or diagnostic center. The procedure involves a healthcare professional drawing a small sample of blood from the expectant mother's arm. The blood sample is then sent to the laboratory, where it undergoes analysis to measure the levels of hCG and PAPP-A. The results are usually available within a few days, after which the expectant mother can discuss the findings with her healthcare provider and determine the next steps.

You may also like: Anomaly Scan: The Ultimate Guide for Expecting Parents

How to Analyze the Double Marker Test Report?

Understanding the double marker test report requires careful consideration of several factors. The report typically includes the measured levels of hCG and PAPP-A, along with the calculated risk for Down syndrome and Edwards syndrome. It is important to remember that the double marker test provides an estimate of risk, not a definitive diagnosis.

The risk is usually expressed as a ratio or as a probability (e.g., 1 in 500 or 0.2%). Screen positive signifies that there is a strong probability that the baby will have the situation if the balance is between 1:10 and 1:250. A screen negative result is one in which the likelihood of a child being born with a chromosomal or neurological abnormality is less than one in a thousand.

Understanding the Double Marker Test Results

The interpretation of double marker test results depends on various factors, including the measured levels of hCG and PAPP-A, maternal age, gestational age, and any additional risk factors. Healthcare providers use these results to categorize the risk as low, intermediate, or high.

It is crucial to highlight that a high-risk result does not indicate the presence of chromosomal abnormalities definitively. Instead, it suggests a higher probability and may prompt further diagnostic tests like amniocentesis or chorionic villus sampling (CVS) for a definitive diagnosis. A low-risk result, on the other hand, provides reassurance but does not guarantee the absence of chromosomal abnormalities.

1. Double Marker Test Normal Values

The normal values for hCG and PAPP-A can vary slightly depending on the specific laboratory and the gestational age at the time of testing. However, in general, hCG levels are expected to be lower, while PAPP-A levels are expected to be higher in unaffected pregnancies. It is important to note that expectant mothers should consult their healthcare provider to understand the specific normal values used by their laboratory and the implications for their individual case.

2. Double Marker Test Negative Means

A negative double marker test result indicates a low probability of Down syndrome and Edwards syndrome. This result provides reassurance to expectant parents and suggests a reduced need for further diagnostic tests. However, it is important to remember that the test cannot rule out these conditions entirely, and there is still a small chance of false negatives.

3. Double Marker Test Positive Means

A positive double marker test result suggests an increased risk of Down syndrome and Edwards syndrome in the fetus. However, it is important to remember that a positive result is not a definitive diagnosis. It indicates a higher probability and may prompt further diagnostic tests, such as amniocentesis or CVS, to confirm or rule out chromosomal abnormalities. A positive result can be distressing for expectant parents, but it is essential to seek guidance from healthcare providers who can provide accurate information, counseling, and support throughout the decision-making process.

Next Steps

After receiving the double marker test report, expectant mothers should promptly schedule a follow-up appointment with their healthcare provider. During this consultation, the healthcare provider will review the results, discuss the implications, and provide appropriate guidance based on the individual circumstances.

The next steps may involve further diagnostic tests, additional screenings, or regular monitoring to ensure the well-being of both the mother and the baby. It is crucial for expectant parents to openly communicate their concerns and questions to their healthcare provider to make informed decisions and receive the necessary support throughout the journey of pregnancy.

FAQs

1. Can Double Marker Test in Pregnancy be Dangerous?

The double marker test is considered safe and poses minimal risks to both the mother and the baby. It is a non-invasive blood test that does not involve any invasive procedures or exposure to radiation. However, as with any medical test, there may be a slight risk of bruising, bleeding, or infection at the site where the blood sample is taken.

2. What is the Difference Between Double Marker and Triple Marker Test?

The double marker and the triple marker test are both blood tests performed during pregnancy to assess the risk of chromosomal abnormalities. While the double marker measures two specific markers (hCG and PAPP-A), the triple marker test measures three markers (hCG, alpha-fetoprotein, and unconjugated estriol). The triple marker test is usually performed between the 15th and 20th weeks of pregnancy and provides additional information about the risk of neural tube defects.

3. Can Double Marker Test be Done After 14 Weeks?

The ideal double marker test time is between the 10th and 14th weeks of pregnancy. This specific time frame is chosen because the levels of hCG and PAPP-A are known to be stable during this period, providing reliable results. However, in certain circumstances, the test can still be performed after the 14th week. It is essential for expectant mothers to consult their healthcare provider to determine the most appropriate time for the test based on their individual circumstances.

The Bottomline

The double marker test is a valuable tool in assessing the risk of chromosomal abnormalities during pregnancy, particularly Down syndrome and Edwards syndrome. It is crucial to remember that the double marker test in pregnancy provides an estimate of risk, not a definitive diagnosis. Therefore, it is essential to consult with healthcare providers, discuss the results, and determine the most suitable next steps based on individual circumstances. With proper prenatal care and support, expectant mothers can optimize the health and well-being of both themselves and their precious little ones.

References

1. Shiefa S, Amargandhi M, Bhupendra J, Moulali S, Kristine T. (2013). First Trimester Maternal Serum Screening Using Biochemical Markers PAPP-A and Free β-hCG for Down Syndrome, Patau Syndrome and Edward Syndrome. Indian J Clin Biochem.

2. Phadke SR, Puri RD, Ranganath P. (2017). Prenatal screening for genetic disorders: Suggested guidelines for the Indian Scenario. Indian J Med Res.

3. Durković J, Ubavić M, Durković M, Kis T. (2018). Prenatal Screening Markers for Down Syndrome: Sensitivity, Specificity, Positive and Negative Expected Value Method. J Med Biochem.