Many women feel uncertain about the position and condition of the foetus during the initial pregnancy tests. During pregnancy, the developing foetus can have chromosomal abnormalities that may lead to multiple complications. Chromosomal abnormalities occur due to the incorrect number of chromosomes, wrong genetic information within a chromosome, or structural issues in the chromosomes. To detect such issues, the double marker test involves taking a sample of your blood to ensure safe growth for your baby.
Understanding how these tests work and how you can best prepare brings more clarity about the screening.
What is the Double Marker Test?
The double marker test in pregnancy determines the risks of chromosomal abnormalities in the foetus. The screening measures free beta-hCG (beta-human chorionic gonadotropin) and PAPP-A (pregnancy-associated plasma protein A) levels. The altered presence of these markers in the blood may indicate the risk of chromosomal abnormalities such as Down Syndrome and Edward’s Syndrome.
Why is it Called a Double Marker Test?
The name ‘Double Marker Test’ comes from the fact that it measures two specific markers in women’s blood during pregnancy. Substances like free beta-hCG and PAPP-A are checked together to give doctors an idea about your baby’s likelihood of having genetic conditions.
Purpose of the Double Marker Test
The main purpose of the dual marker test is to determine the health of your baby. It does not confirm that your baby has the genetic conditions, but it helps doctors to understand if the pregnancy is at low risk or high risk.
Another double marker test purpose is to provide you with clarity about your pregnancy by flagging potential risks early. It helps to determine the severity of risk and suggests to you the possible steps you can take to avoid them.
What Does It Detect?
The double marker test in pregnancy helps to detect the risk of genetic conditions in your baby, which are Down Syndrome and Edwards Syndrome. Children with these syndromes often face challenges related to intellectual and physical growth.
This test can also detect the likelihood of Patau Syndrome (Trisomy 13), which is a rarer chromosomal disorder linked with multiple developmental issues. By identifying these issues at an early stage, doctors can recommend further diagnostic screenings or tests.
Who Should Take the Test?
Doctors suggest that the double marker test should be taken by women who are in their first trimester of pregnancy. This screening is especially recommended if you are above 35 years old and have a family history of genetic issues.
It is also advised for expectant mothers who have experienced previous pregnancy complications or have found abnormal ultrasound screening results. Even for women without obvious risk factors, this test provides reassurance and helps you plan a safe pregnancy journey.
When is the Double Marker Test Done?
The double marker test is usually done during the 9th and 13th weeks of pregnancy. This period is best for measuring both the blood markers and your baby’s nuchal translucency (NT) on ultrasound.
Together, these results help you to get clarity about your baby’s risk level for chromosomal abnormalities. Conducting the test during the first trimester ensures maximum accuracy, and you can take valuable steps if there is a possibility of high risk.
What Happens During the Double Marker Test?
The double marker test is a non-invasive way to get valuable information at the early stage of your pregnancy. Together, this screening helps doctors to assess your baby’s vulnerability to genetic conditions in early pregnancy. This process is safe for both the mother and the baby. This screening is done in four steps, which are as follows:
Step 1: Blood Sample Collection
During this step, a doctor collects the blood sample from the mother’s arm. This sample is tested in labs to measure markers like free Beta hCG and PAPP-A.
Step 2: Nuchal Translucency (NT) Ultrasound
After the blood test, an ultrasound scan is performed to measure the thickness of the nuchal translucency (NT) behind your baby’s neck. This fluid-filled space measures the thickness of the fluid to understand the complications during your pregnancy.
This scan is completed between the 11th and 14th weeks of pregnancy. The NT ultrasound scan also helps to confirm the baby’s gestational age and check for other early developmental markers.
Step 3: Combining the Results
The results of the blood test and ultrasound are analysed with the mother’s age and medical history. This combined report provides the estimate of possible risks. Results are provided in ratios, which show the chances of the baby having the genetic conditions.
Step 4: Discussion With the Doctor
Once the double marker test result is ready, your doctor will explain the results and recommend further screenings or tests if they have found any issues. This whole process helps you to understand the findings and next steps of the pregnancy screening.
Interpreting the Double Marker Test Results
The double marker tests do not give you simple positive or negative results. Instead, it provides a risk estimate for conditions such as Down Syndrome and Edwards Syndrome. The results of this screening are usually categorised as low risk or high risk.
Normal vs Abnormal Results
The double marker test normal values are reported as risk ratios, showing it as 1:250 or 1:1000. This result shows the chances of chromosomal abnormalities in your baby. If the ratio shows 1:1000, it means that there is a 1 in 1000 chance of your baby having the condition.
| Risk Category | Description |
| Normal Results (Low Risk) | The double marker test normal range suggests a minimal chance of genetic issues; this report can look similar to the ratio of 1:1000 or higher. |
| Abnormal Results (High Risk) | A high-risk result increases the chances of chromosomal abnormalities, and it can be shown to be similar to the ratio of 1:250 or lower. |
Next Steps After Abnormal Results
If the screening indicates a higher risk, then your doctor may recommend further diagnostic tests to get an accurate answer. These include chorionic villus sampling (CVS) or amniocentesis for analysing your baby’s chromosomes. Moreover, you may be advised to take another ultrasound scan to check for physical markers.
Benefits of the Double Marker Test
The double marker test offers several advantages, some of which are as follows:
- Safe and Non-Invasive: You only have to give a small blood sample and be prepared for an ultrasound scan.
- Early Detections: These screenings help to detect potential chromosomal severity for beta-hCG and PAPP-A in the first 9th to 13th week of pregnancy.
- Informed Decisions: After estimating the pregnancy risk, you can consider further testing or plan medical care.
- Peace of Mind: After getting results, you can get more clarity about the next steps. Thus, it helps to reduce the worry about the baby’s health.
- Quick and Simple: The screening is simple, and it is often completed within a few minutes in the maternal care units.
These advantages highlight the importance of double marker test in pregnancy, as early detection allows you to get timely medical guidance.
Risks and Limitations
While this test is helpful, the double marker test has some limitations as well. Here are some of them as follows:
- Not a Diagnostic Tool: This screening only estimates the risk, which means a high risk result does not confirm the problem. Also, a low risk result does not ensure everything is fine.
- May Require Follow-Ups: In case you have a high-risk result, you get to take other tests in order to verify the outcome.
- False Positive/Negative: The test can sometimes show high risks where the baby is healthy or vice versa.
- Potential Anxiety: Receiving a high-risk double test result can cause stress or worry for expectant parents. In this case, communication with your doctor is essential to gain a clear idea of the result of screening.
Apart from limitations, this test is safe for both the mother and the baby. So, you can go for this test to know your baby’s health.
Double Marker vs Triple Marker vs Quadruple Test
Prenatal screening helps you to assess the risk of certain chromosomal and developmental conditions of your baby. The most common prenatal screenings are the Double Marker, Triple Marker, and Quadruple Test. While all of them are blood tests, they differ in timing, number of markers analysed and accuracy. Understanding these differences can help you gain more clarity about each of their significance.
Here is the comparison of all of them in a tabular form:
| Test | Typical Timing | Number of Markers | Purpose / Conditions Detected |
| Double Marker | 9th to 13th weeks (first trimester) | 2 (Pregnancy-associated plasma protein A – PAPP-A, and free β-hCG) | Screens for Down syndrome (Trisomy 21) and Trisomy 18 |
| Triple Marker | 15th to 20th weeks (second trimester) | 3 (AFP, hCG, unconjugated oestriol) | Screens for Down syndrome, Trisomy 18, and neural tube defects |
| Quadruple Test | 15th to 20th weeks (second trimester) | 4 (AFP, hCG, unconjugated oestriol, inhibin-A) | Screens for Down syndrome, Trisomy 18, and neural tube defects |
Each test is conducted for different purposes; here they are as follows:
- Double Marker Test: This test is used for early screening of chromosomal abnormalities in babies. Because it is done early, it gives parents more time for additional testing if the results indicate higher risks.
- Triple Marker Test: This test is conducted during the second trimester. This test adds AFP (alpha-fetoprotein) to detect neural tube issues such as spina bifida.
- Quadruple Marker Test: The quadruple marker test includes AFP, Beta hCG, Oestriol and Inhibin-A. This comprehensive test allows you to get additional insights into the risk of certain genetic conditions.
How to Prepare for the Double Marker Test
Getting ready for the double marker test procedure is simple, but you have to understand a few things. Some of them are as follows:
- No fasting is required: You can eat and drink normally before the test unless your doctor has advised special medication.
- Keep handy other ultrasound reports: Carry your previous test results, including the NT scan report. These results may be needed for an accurate risk calculation.
- Wear loose clothing: Since you will be required to roll your sleeves in order to draw a blood sample from your arm, wear something loose.
- Provide your health background: Your physician should know about your medical history and medications so that he/she can give the right results.
- Understand the test is optional: While the double marker test is not mandatory, this result provides important information to guide further pregnancy care.
Conclusion
Double Marker Tests help to determine if you have any pregnancy complications. This test is performed to determine the risks of chromosomal abnormalities in the fetus. If the screening results show high risk, then your doctor may suggest further checks like CVS or amniocentesis. Although this screening is optional, it is a useful step towards ensuring the health and safety of both the mother and the baby.
FAQs
1. What happens in a double marker test?
In the double marker test, a sample of blood is drawn from the arm of the mother to identify the levels of the Beta-hCG and the PAPP-A substances. The results of this test are combined with ultrasound reports and maternal history to analyse the risk of chromosomal abnormalities in the baby.
2. Is there any treatment after a double marker test?
This test alone does not lead to treatment but can help in determining whether further diagnostics or treatment are necessary. In the case that the test results provide a high risk, your doctor may recommend amniocentesis or chorionic villus sampling (CVS) screenings.
3. How much time does a double marker test take?
It rarely takes more than several minutes to collect the blood, and the result is available after 3 to 5 working days. The entire process of consultation and ultrasound may take about an hour if done together.
4. What is the normal range for the double marker test in MoM?
The normal range of free β-hCG chromosomal levels stays between 25,700 – 288,000 mIU/mL. Simultaneously, the ideal range of PAPP-A stays between 0.5 – 2.5 MoM (Multiples of Median).