Pregnancy brings excitement, anticipation, and naturally, questions about the health of the baby. One of the most common concerns expectant mothers have is simple:

“Is my baby developing normally?”

Today, advances in prenatal screening allow doctors to assess certain risks early in pregnancy, often before any symptoms or complications appear. One of the most commonly recommended first trimester screening tests is the Dual Marker Test.

At National Path Lab, the Dual Marker Test in Nepal is available as part of early maternal screening and prenatal risk assessment.

What is the Dual Marker Test?

The Dual Marker Test is a prenatal blood screening test performed during early pregnancy to assess the risk of certain chromosomal abnormalities in the fetus.

The test primarily evaluates the likelihood of conditions such as:

• Down Syndrome (Trisomy 21)

• Edwards Syndrome (Trisomy 18)

• Patau Syndrome (Trisomy 13)

Importantly, the Dual Marker Test is a screening test, not a final diagnosis. It estimates risk and helps determine whether further testing may be necessary.

What Do These Conditions Mean?

Down Syndrome (Trisomy 21)

Down syndrome occurs when there is an extra copy of chromosome 21.

Children with Down syndrome may experience:

• Delayed intellectual development

• Learning difficulties

• Distinct facial features

• Reduced muscle tone

• Delayed speech development

• Congenital heart defects in some cases

With appropriate medical care, therapy, and support, many individuals with Down syndrome can lead meaningful and active lives.

Edwards Syndrome (Trisomy 18)

Edwards syndrome is a more severe chromosomal condition caused by an extra chromosome 18.

It can affect multiple organ systems and may lead to:

• Low birth weight

• Heart abnormalities

• Kidney problems

• Brain development issues

• Severe developmental complications

Many affected pregnancies face serious medical challenges during pregnancy or shortly after birth.

Patau Syndrome (Trisomy 13)

Patau syndrome results from an extra chromosome 13 and is considered a severe chromosomal disorder.

It may cause:

• Brain development abnormalities

• Cleft lip or palate

• Congenital heart defects

• Eye abnormalities

• Multiple structural complications

In many cases, long-term survival is limited due to the severity of associated conditions.

Is the Dual Marker Test Mandatory?

No.

The Dual Marker Test is optional and depends on the parents’ decision after consultation with their doctor. However, it is commonly recommended as part of first trimester prenatal testing, particularly in higher-risk pregnancies.

Doctors may strongly advise the test in situations such as:

• Maternal age above 35 years

• Previous pregnancy affected by chromosomal abnormalities

• Family history of genetic conditions

• Abnormal ultrasound findings

• Increased nuchal translucency (NT) thickness on ultrasound

In some higher-risk situations, doctors may recommend proceeding directly to more advanced screening methods such as NIPT (Non-Invasive Prenatal Testing).

When is the Dual Marker Test Done?

The Dual Marker Test is performed between:

11 weeks to 13 weeks + 6 days of pregnancy

Timing is important because the accuracy of the test depends on gestational age.

What Information is Needed for the Test?

The Dual Marker Test combines multiple pieces of information to calculate risk accurately.

1. Maternal Information

This includes:

• Age

• Weight

• Ethnic background

• Diabetes status

• Smoking history

• Whether pregnancy occurred naturally or through IVF/ART

2. Ultrasound Findings

Specific ultrasound markers are included, such as:

• Crown-rump length (CRL)

• Nuchal translucency (NT)

• Presence or absence of the nasal bone

An increased NT thickness may indicate a higher risk of chromosomal abnormalities.

3. Maternal Blood Test

Two biochemical markers are measured from the mother’s blood:

• Free Beta-hCG

• PAPP-A (Pregnancy-Associated Plasma Protein A)

Because both are linked to placental development, abnormal levels may indicate increased chromosomal risk.

For best accuracy, blood collection and ultrasound are ideally performed on the same day or close together.

How Does the Report Work?

All collected data is analyzed using specialized risk assessment software.

The system compares the findings with established statistical standards and calculates the estimated risk.

Results are often reported as ratios, such as:

1:100

This means there is an estimated 1 in 100 chance that the fetus may have one of the screened chromosomal conditions.

Different laboratories and software systems may use different cut-off values, including:

• 1:250

• 1:350

Reports may classify results as:

• Low Risk

• Intermediate Risk

• High Risk

Because interpretation can be complex, results should always be discussed with a qualified doctor rather than interpreted independently.

What Happens if the Result Shows High Risk?

A high-risk result does not mean the baby definitely has a chromosomal condition.

It simply indicates that further testing may be recommended.

Depending on the case, doctors may suggest:

• NIPT (Non-Invasive Prenatal Testing)

• Amniocentesis

NIPT offers a more advanced non-invasive screening approach, while amniocentesis provides diagnostic confirmation through invasive testing.

Is Fasting Required?

No.

The Dual Marker Test does not require fasting. Pregnant women can eat normally before sample collection.

The blood collection itself usually takes only a few minutes and does not harm either the mother or the baby.

Why Prenatal Screening Matters

Prenatal screening helps families and clinicians make informed decisions early in pregnancy.

While screening tests cannot diagnose every condition, they play an important role in:

• Early risk assessment

• Pregnancy planning

• Timely specialist referral

• Reducing uncertainty during pregnancy

Combined with anomaly scans and medical consultation, these tests support more informed maternal and fetal care.

Dual Marker Test in Nepal at National Path Lab

At National Path Lab, prenatal screening services are performed using internationally aligned diagnostic standards and experienced laboratory professionals.

Our maternal screening services support:

• Early pregnancy risk assessment

• Chromosomal screening

• Advanced prenatal diagnostics

• Timely reporting

• Professional consultation support

For more information regarding the Dual Marker Test in Nepal, sample collection, or prenatal screening services, contact National Path Lab.