How to Interpret Your Dual Marker Test Report: A Simple Guide for Pregnant Women
Updated: Sep 30
How to Interpret Your Dual Marker Test Report: A Simple Guide for Pregnant Women
If you are pregnant and have recently received your dual marker test report, you may be wondering what all those numbers and terms mean. Words such as PAPP-A, free beta-hCG, MoM, risk ratio, and Trisomy 21 can be confusing.
The good news is that the dual marker test is a screening test, not a diagnostic test. Its purpose is to estimate whether your pregnancy has a higher or lower chance of certain chromosomal conditions.
This guide explains how to understand your dual marker test report in simple terms.
What is the dual marker test?
The dual marker test, also called the first-trimester combined screening test, is usually performed during early pregnancy.
It combines:
* A blood test measuring PAPP-A (Pregnancy-Associated Plasma Protein-A)
* A blood test measuring free beta-hCG
* Your age
* Pregnancy details
* Ultrasound findings, especially the nuchal translucency (NT) measurement
These factors are used to calculate the estimated risk of chromosomal conditions, particularly:
* Trisomy 21 (Down syndrome)
* Trisomy 18 (Edwards syndrome)
* Trisomy 13 (Patau syndrome)
Is the dual marker test a diagnostic test?
No.
This is one of the most important things to understand.
The dual marker test is a screening test. It does not confirm whether your baby has a chromosomal condition.
A report indicating “high risk” does not mean that your baby definitely has the condition.
Similarly, a “low-risk” result does not completely eliminate the possibility.
If your screening result indicates an increased risk, your doctor may discuss additional testing such as NIPT (Non-Invasive Prenatal Testing) or, depending on the situation, diagnostic tests such as chorionic villus sampling (CVS) or amniocentesis.
⸻
Understanding the main values in your report
1. PAPP-A
PAPP-A is a protein produced by the placenta during pregnancy.
Your report may show:
* The measured PAPP-A level
* The MoM (Multiples of the Median) value
The MoM value adjusts the result according to factors such as gestational age and other maternal characteristics.
A PAPP-A value that is lower than expected can be associated with an increased chance of certain chromosomal conditions and, in some pregnancies, placental complications.
However, a low PAPP-A by itself does not mean that your baby has a chromosomal abnormality.
Your doctor interprets it together with the ultrasound and other factors.
2. Free beta-hCG
Free beta-hCG is another pregnancy-related hormone measured in the blood.
Like PAPP-A, it is commonly reported as a MoM value.
An unusually high or low value may influence the calculated screening risk, but it should never be interpreted in isolation.
The laboratory combines the marker results with other information to calculate an overall risk.
⸻
What does MoM mean?
You may see a number such as:
PAPP-A: 0.65 MoM
or
Free beta-hCG: 1.8 MoM
MoM means “Multiples of the Median.”
In simple terms, it compares your result with the expected median value for pregnancies at a similar stage.
A MoM around 1.0 is approximately the median.
Values above or below 1.0 may influence the risk calculation, but there is no single MoM number that can be used by itself to diagnose a problem.
The interpretation depends on the complete screening calculation.
⸻
What is the risk ratio?
This is often the most confusing part of the report.
Your report may say something like:
Trisomy 21: 1 in 1,000
or
Trisomy 21: 1 in 100
These numbers represent the estimated chance, not a diagnosis.
For example:
1 in 1,000
This means that, based on the screening calculation, approximately 1 pregnancy out of 1,000 with similar characteristics would be expected to have the condition.
1 in 100
This represents a higher estimated chance: approximately 1 pregnancy out of 100.
Therefore, a smaller denominator generally represents a higher estimated risk.
However, whether a result is classified as screen positive or screen negative depends on the screening program and laboratory’s specified cutoff.
⸻
What does “low risk” mean?
A result described as low risk means that the calculated chance of the screened chromosomal conditions is below the laboratory’s screening threshold.
For example, a report may show:
Trisomy 21: 1 in 5,000 – Low risk
This is reassuring, but it does not mean zero risk.
No screening test can detect every affected pregnancy.
Your doctor will consider the result along with your ultrasound findings and the rest of your pregnancy care.
⸻
What does “high risk” or “screen positive” mean?
A high-risk or screen-positive result means that the calculated chance is above the laboratory’s chosen screening threshold.
It does not mean your baby definitely has Down syndrome or another chromosomal condition.
For example, a result of:
Trisomy 21: 1 in 80
means the estimated chance is higher than a result of 1 in 1,000.
It is a reason to discuss further evaluation with your obstetrician—not a reason to panic.
Your doctor may recommend or discuss options such as:
* Reviewing the NT and other ultrasound findings
* NIPT
* Genetic counselling
* CVS
* Amniocentesis
The appropriate next step depends on your individual pregnancy.
⸻
Why is the NT scan important?
The dual marker blood test is generally interpreted together with the first-trimester ultrasound, particularly the nuchal translucency (NT) measurement.
NT measures the fluid-filled space at the back of the baby’s neck.
The combined screening assessment may therefore include:
Maternal age + NT measurement + PAPP-A + free beta-hCG + other pregnancy information
This combined approach provides a more meaningful risk assessment than looking at either blood marker alone.
⸻
What if my NT is normal but my dual marker is abnormal?
This situation can cause considerable anxiety.
Remember that the blood markers and NT are screening components, not diagnostic tests.
An isolated abnormal marker does not automatically mean that your baby has a chromosomal abnormality.
Your obstetrician will look at the complete screening result, including the calculated risk ratio, ultrasound findings, gestational age, and other relevant factors.
Depending on the overall result, further screening or diagnostic testing may be discussed.
⸻
What if my dual marker is low risk?
A low-risk result is reassuring.
Continue your routine antenatal care and follow your doctor’s recommendations for subsequent ultrasound scans and screening.
Depending on your pregnancy and medical history, your doctor may recommend additional screening later in pregnancy.
⸻
Dual marker test vs NIPT
Both are screening tests, but they are different.
Test What it uses Purpose
Dual marker Maternal blood + ultrasound/clinical information Estimates risk of common chromosomal conditions
NIPT Cell-free fetal DNA in maternal blood More accurately screens for certain common chromosomal conditions
CVS Placental tissue Diagnostic testing
Amniocentesis Amniotic fluid Diagnostic testing
NIPT is also a screening test, not a definitive diagnostic test.
CVS and amniocentesis are diagnostic procedures and are generally considered when there is an appropriate clinical indication.
⸻
Don’t interpret one number on your own
One of the most common mistakes is looking at only the PAPP-A or beta-hCG value and trying to decide whether the pregnancy is normal.
The report needs to be interpreted as a whole.
Your doctor may consider:
* Your age
* Gestational age
* NT measurement
* PAPP-A MoM
* Free beta-hCG MoM
* Calculated risk for Trisomy 21
* Calculated risk for Trisomy 18
* Calculated risk for Trisomy 13
* Ultrasound findings
* Previous pregnancy and medical history where relevant
⸻
When should you speak to your doctor?
Discuss your report with your obstetrician if:
* The report says high risk
* The report says screen positive
* NT is increased
* You are unsure what your risk ratio means
* Your doctor has recommended NIPT or diagnostic testing
* You have received conflicting information from the report and ultrasound
Do not make decisions about your pregnancy based on a single number on the report.
⸻
The most important message
A dual marker test is a risk assessment—not a diagnosis.
A low-risk result does not guarantee that a baby has no chromosomal condition, and a high-risk result does not confirm that the baby has one.
The correct interpretation comes from looking at the complete report together with the ultrasound findings and your individual pregnancy circumstances.
If you have received a dual marker report that you do not understand, take it to your obstetrician or a qualified prenatal screening/genetic counselling professional. They can explain what your individual result means and whether any further testing is appropriate.
Frequently Asked Questions
Is a dual marker test mandatory?
No. Prenatal screening options should be discussed with your obstetrician so you can make an informed decision appropriate for your pregnancy.
What is a normal dual marker result?
There is no single “normal” PAPP-A or beta-hCG value that applies to every pregnancy. The values are adjusted and interpreted as part of an overall risk calculation.
Is 1 in 100 a high risk?
It represents a higher estimated chance than 1 in 1,000, but whether it is classified as screen positive depends on the laboratory’s cutoff and the screening protocol used.
Can a low-risk dual marker result guarantee a healthy baby?
No. It reduces the estimated chance of the screened conditions but cannot rule them out completely.
What should I do if my dual marker is high risk?
Speak with your obstetrician. Depending on the complete result and your circumstances, they may discuss NIPT, genetic counselling, or diagnostic testing such as CVS or amniocentesis.
Can I understand my report without seeing my doctor?
You can understand the basic terms, but an individual result should be interpreted in its clinical context. Your obstetrician can explain what the calculated risk means for your pregnancy and whether further evaluation is appropriate.
About the Author
Dr. Anuradha Narayanan is an experienced Gynaecologist & Obstetrician in Mumbai, dedicated to compassionate women’s healthcare, pregnancy care and patient education.
Anurag Women Health Care, Chembur, Mumbai
Comments