Dr. Aruna Ashok MBBS, MS OG, DNB OG
- Clinical Director
Aruna Ashok | 04 Dec 2026
During pregnancy, it is completely normal to feel overwhelmed or concerned when it comes to encountering new medical terms. The journey to motherhood is a transformative experience that involves learning a lot in various aspects, not just nutrition.
That’s why we are here to help you with one such term, “double marker test”. It is otherwise known as the dual marker test.
The Double Marker Test is a non-invasive blood test recommended for pregnant women. The test is usually performed to measure the levels of Free β-hCG and PAPP-A. These are the hormones secreted by the placenta. Its levels are measured to assess the risk of chromosomal abnormalities in the developing fetus. They may include:
The double marker test is often combined with a nuchal translucency (NT) ultrasound scan for a more accurate assessment.
However, it is important to understand that the double marker test is a screening test, meaning it only indicates the risk. It cannot be considered a definite diagnostic procedure. For an accurate diagnosis, further investigation may be recommended by the healthcare provider if the assessment has a higher risk.
The standard timeline for performing a double marker test is between 11 and 14 weeks of pregnancy, along with the NT scan. The most accurate window is widely considered between 11 and 13 weeks.
The double marker test is important in prenatal care because:
It helps to identify potential genetic issues in the developing fetus very early.
It helps to determine the probability of chromosomal abnormalities in the fetus, especially Trisomy 21 (Down Syndrome), Trisomy 18 (Edward Syndrome), and Trisomy 13 (Patau Syndrome).
It provides significant information about the fetal health that helps parents to decide on the further diagnostic options, or about continuing the pregnancy, or preparing for potential complications.
For couples with low-risk results, it provides peace of mind by reducing anxiety.
The combination of the double marker test and NT scan delivers the most accurate risk assessment. This is highly possible when performed at the ideal window (around 11-14 weeks).
The double marker test is a widely recommended screening for all pregnant women during their first trimester of prenatal care. However, it is particularly recommended for:
This is because it is believed that advanced maternal age increases the risk of chromosomal abnormalities.
Parents having a history of chromosomal issues or birth defects.
A previous pregnancy with any genetic abnormalities makes this screening mandatory in the present pregnancy.
Identifying potential issues in the prenatal ultrasounds often prompts doctors to strongly recommend this screening.
Couples using assisted reproductive technologies like IVF to achieve pregnancy
Parents who desire to have early insights for making informed decisions or peace of mind
The double marker test, or dual marker test, is a non-invasive blood test. It basically measures the levels of two hormones, namely free β-hCG and Pregnancy-Associated Plasma Protein-A (PAPP-A). A higher level of β-hCG and a lower level of PAPP-A in the maternal blood can signal an increased risk of chromosomal abnormalities in the fetus.
The following procedures describe how the test is done.
A medical professional or healthcare provider may collect a sample of blood from your arm vein.
Note: The test usually requires no fasting unless recommended by your doctor.
Along with it, an ultrasound is performed to measure the levels of fluid in the back of the baby’s neck. It also checks the development of the nasal bone. These findings are the soft markers for the risk assessment.
The collected blood sample is analysed to measure both free β-hCG and PAPP-A.
A software specifically designed for the dual marker test is used to calculate the risk using the mother’s age, gestational age, NT scan measurements, and blood test results.
The results are interpreted, indicating low, moderate, or high risk.
A double marker test results are usually categorised by the risk levels. This helps the healthcare providers to determine the likelihood of the developing baby having genetic conditions.
The key assessment of interpreting the double marker test results may include:
The results are generally expressed as ratios. When it comes to low risk, the result can be more than 1:250. This means that your child has a very low chance of abnormality. It is considered a normal and reassuring outcome.
Ratios like 1:250 or lower than that may typically mean that your child has a higher chance of abnormality. It usually warrants further screening or diagnosis.
It is important to understand that the double marker test is performed only to identify the risk. Based on it, further investigation may be prompted for the definitive diagnosis. In simple terms, only with the abnormal double marker test result, doctors may not start immediate treatment for the condition itself. Instead, they recommend further investigation.
After a double marker test, follow-up options depend on the risk level.
If the risk is low, you may usually be recommended to continue with the regular prenatal care. This is because low-risk results are often reassuring that your child has a very minimal risk of having any genetic disorders.
A moderate-to-high-risk result often means that your child has a higher chance of having genetic disorders. This demands a definite diagnosis. Your healthcare provider may generally recommend:
Further screening, such as Non-Invasive Prenatal Testing (NIPT), is suggested for refined screening.
Diagnostic testing, such as Amniocentesis or Chorionic Villus Sampling (CVS), may be recommended for definitive results.
Based on the results, the counselling is offered. This helps couples to understand the actual implications and make informed decisions. It can be about continuing the pregnancy or preparing for potential complications.
Apart from the double marker test, other prenatal tests for chromosomal abnormalities may include:
| Test | Type | Timing | Method | Purpose | Accuracy |
|---|---|---|---|---|---|
| Nuchal Translucency (NT) Scan | Screening | 11–14 weeks | Ultrasound – measures the level of fluid at the back of the baby's neck. | Screens for risk of Down syndrome, Trisomy 18, and Trisomy 13. | 70-80% accurate when done alone. If paired with first-trimester blood tests (PAPP-A, hCG), it can provide 90-95% accurate results. |
| Triple Marker Test | Screening | 15–20 weeks | Blood test – measures AFP, hCG, and uE3. | Screens for risk of Down syndrome, Trisomy 18, and neural tube defects. | 70-80% accurate. |
| Quadruple Marker Test | Screening | 15–22 weeks | Blood test – measures AFP, hCG, uE3, and Inhibin-A. | Screens for risk of Down syndrome, Trisomy 18, and neural tube defects. | 80-90% for Down syndrome and 75% for neural tube defects. |
| Non-Invasive Prenatal Testing (NIPT) | Screening | As early as 10 weeks | Blood test – analyses cell-free fetal DNA. | Screens for Down syndrome, Trisomy 18, and Trisomy 13. It can also detect chromosomal abnormalities in the sex chromosomes. | >99% accurate. |
| Integrated/Sequential Screening | Screening | 1st and 2nd Trimesters | Combines NT scan results with blood tests from the first or second trimester. | Screens for risk of Down syndrome, Trisomy 18, and neural tube defects. | Up to 96% accurate. |
| Chorionic Villus Sampling (CVS) | Diagnostic | 10–13 weeks | Placental tissue sample collected through a needle guided by ultrasound. | Provides a definitive diagnosis of chromosomal abnormalities. | >99% accurate. |
| Amniocentesis | Diagnostic | 15+ weeks | Amniotic fluid sample collected through a needle guided by ultrasound. | Provides a definitive diagnosis of chromosomal abnormalities and neural tube defects. | >99% accurate. |
The double marker test in pregnancy is a safe, prenatal blood test. It is a valuable screening for assessing the possibilities of chromosomal abnormalities in the child. It poses no risk to the mother and the child. It is just a simple blood test drawn from the arm vein. Assessing the risk of conditions like Down (21), Edwards (18), and Patau (13) syndromes provides expecting parents with early information about their child’s health.
1. What is the cost of a double marker test in Chennai?
The cost of a double marker test may vary depending on the facility. Generally, the cost can range from ₹1700 to ₹4000 in Chennai
2. Is the double marker test painful?
The answer to the question is no. The double marker test is usually not painful. It is similar to a regular blood test, where blood is drawn from a vein in the arm. It can cause mild discomfort at the prick site, though it is temporary.
3. How long will the double marker test take?
The double marker test may often take about 5 to 10 minutes.
4. When will the results of the double marker test be available?
The results of the double marker test are generally available in 2 to 7 days. In some laboratories, it can be available within 24 to 48 hours. These timelines may widely vary depending on the lab and location
5. Can the double marker test identify autism?
The answer to the question is no. The double marker test (dual marker test) cannot directly diagnose autism (ASD). The test is performed to screen for chromosomal issues like Down syndrome, not autism. Autism is a complex neurodevelopmental disorder. It involves various assessment factors, not just a single blood test
