When should I take the double marker test?

The double marker test is usually done between 11 and 14 weeks of pregnancy, often along with a nuchal translucency (NT) scan.

Are double and quad marker tests safe for me and my baby?

Yes, both tests are simple blood screenings and are non-invasive and safe for you and your baby.

Can a quad screen test in pregnancy detect all birth defects?

No, the quadruple marker test mainly focuses on certain chromosomal and neural tube conditions. It does not screen for all types of genetic disorders or physical abnormalities.

Double and Quad Marker Tests in Pregnancy: What They Detect & When

Pregnancy is an exciting journey filled with hope and anticipation. But alongside the joy, there's also the responsibility of keeping track of your baby’s health. Among the many prenatal tests available, the double and quadruple marker tests are important screening tools. They help check the risk of certain genetic or developmental conditions in your unborn baby. Done at different stages, these blood tests give useful information that helps you and your doctor plan the next steps with confidence.

What Are the Double and Quadruple Marker Tests?

The double and quadruple marker tests are blood tests used during pregnancy to screen for potential chromosomal and developmental abnormalities in your baby. They measure specific substances in your blood, known as markers, to estimate the risk of conditions like Down syndrome (Trisomy 21), Edward’s syndrome (Trisomy 18), and neural tube defects such as spina bifida.

These are screening tests, not diagnostic ones. This means they indicate the possibility of a condition rather than confirming it. If results suggest a higher risk (screen positive), your doctor may recommend further tests to get a clearer picture. These are non-invasive blood tests, safe for both you and your baby.

When Are These Tests Done?

The double and quadruple marker tests are performed at different stages of your pregnancy to provide timely information about your baby’s health.

Double marker test: This test is done in the first trimester, between 11 and 14 weeks of pregnancy. It’s often paired with a nuchal translucency (NT) scan, which uses ultrasound to measure fluid at the back of your baby’s neck for a more complete screening.
Quadruple marker test: This test takes place in the second trimester, ideally between 15 and 20 weeks, with the most accurate results between weeks 16 and 18. It builds on earlier screenings by checking for additional markers.

Timing matters with both tests because the levels of these markers change as your pregnancy progresses. Taking them at the right stage helps give more accurate results and clearer insights.

What Do These Tests Measure?

The double marker test focuses on two markers, while the quadruple marker test looks at four. With more markers, the quadruple test offers a broader picture of your baby’s risk for certain conditions.

Double Marker Test Markers

Free Beta Human Chorionic Gonadotropin (hCG): A hormone produced by the placenta. Higher-than-normal levels may indicate a risk of Down syndrome.
Pregnancy-Associated Plasma Protein-A (PAPP-A): A protein made during pregnancy. Lower levels can suggest a higher risk of chromosomal abnormalities like Down syndrome or Edward’s syndrome.

Quadruple Marker Test Markers

Alpha-Fetoprotein (AFP): Produced by your baby’s liver, high levels may point to neural tube defects like spina bifida, while low levels could indicate Down syndrome. High AFP might also suggest twins or a more advanced pregnancy.
Unconjugated Estriol (uE3): A hormone made by the placenta and your baby’s liver. Low levels are linked to a higher risk of Down syndrome.
Human Chorionic Gonadotropin (hCG): Also measured in the double marker test, higher-than-normal levels in the quad screen can indicate Down syndrome risk.
Inhibin-A: A protein produced by the placenta and ovaries. Elevated levels are associated with a higher risk of Down syndrome.

Who Should Get These Tests?

Both tests are optional, but they’re recommended for all pregnant individuals to monitor foetal health. They’re especially important if you have certain risk factors, such as:

Being over 35 years old, as the risk of chromosomal abnormalities increases with age.
A family history of genetic disorders or congenital disabilities.
A diagnosis of type 1 diabetes during pregnancy.
Exposure to harmful medications, high levels of radiation, or a viral infection during pregnancy.

Even without these risk factors, the tests offer valuable reassurance and help make sure your baby is developing healthily.

Double and quadruple marker tests are important early screening tools during pregnancy. They measure specific markers in your blood to estimate the risk of certain conditions in your baby. While they don’t give a definite diagnosis, they can indicate if further testing is needed. These screenings are safe, non-invasive, and provide useful information to help you and your doctor make informed decisions.

FAQs on What Double and Quad Marker Tests Measure During Pregnancy

When should I take the double marker test?
The double marker test is usually done between 11 and 14 weeks of pregnancy, often along with a nuchal translucency (NT) scan.
Are double and quad marker tests safe for me and my baby?
Yes, both tests are simple blood screenings and are non-invasive and safe for you and your baby.
Can a quad screen test in pregnancy detect all birth defects?
No, the quadruple marker test mainly focuses on certain chromosomal and neural tube conditions. It does not screen for all types of genetic disorders or physical abnormalities.