Blood tests are frequently employed during pregnancy as a diagnostic tool. They provide a safe way to understand various factors that may impact the developing foetus, enabling parents and healthcare professionals to keep track of growth, development, and any potential concerns. If you are in your second trimester, your doctor may recommend a quadruple marker test. While this test is not mandatory, it offers valuable insights into the health of your unborn baby by analysing the levels of four specific substances in your blood.

What is the Quadruple Marker Test?

The quadruple marker test, often called a quad screen, is a blood test conducted during the second trimester of pregnancy (between 15 and 20 weeks) to detect possible birth defects or chromosomal abnormalities in the unborn baby.

This test evaluates the levels of four specific substances in the mother's blood:

1. Unconjugated estriol (uE3)
2. Alpha-fetoprotein (AFP)
3. Inhibin-A
4. Human chorionic gonadotropin (hCG)

AFP is a hormone made by the developing foetus, while hCG, uE3, and inhibin-A are produced by the placenta.
The quadruple marker test can help assess the risk of certain conditions in the foetus, such as Down's syndrome, trisomy 18 (Edward's syndrome), and neural tube defects. It can also assist in identifying multiple pregnancies and monitoring the overall health of both the mother and the foetus.

Although the test is typically considered safe, there is a possibility of false-positive results. Therefore, it is advisable to discuss the potential risks and benefits with your healthcare provider before making a decision about the test.

Why should I opt for the Quad Marker Screen?

Although it is generally recommended for all pregnant women to consider the quad marker screen, the decision is ultimately yours. However, if you have any of the following risk factors, you might want to think seriously about having the test:

• You are 35 years old or older when your baby is due.
• You have had a previous child with a birth defect.
• You were diagnosed with type 1 diabetes before becoming pregnant.
• There is a personal or family history of congenital disabilities.
• You have taken certain medications or substances that could pose risks.
• You use insulin.
• You have had a viral fever or infection during your pregnancy.
• You have been exposed to significant levels of radiation.

Why is a Quadruple Marker Test Done?

The quadruple marker test is performed to identify four specific markers that may indicate the presence of birth defects in the foetus. This test evaluates the risk of the foetus developing four significant conditions:

• Down's syndrome (Trisomy 21): This chromosomal disorder can cause a range of developmental delays, lifelong intellectual disabilities, and associated health challenges.
• Edward's syndrome (Trisomy 18): This condition is characterised by slower growth and various physical abnormalities. It is often fatal before birth or within the first year of life, with no available treatment.
• Spina bifida: This occurs when the spinal cord of the foetus does not develop or close properly in the womb, potentially leading to paralysis of the lower limbs and, in some cases, learning difficulties.
• Abdominal wall defects: These defects involve issues with the foetus's abdominal wall, which may result in the intestines or other abdominal organs protruding from the belly button.

The test is an important tool for assessing these risks, helping parents and healthcare providers make informed decisions about any necessary follow-up tests or management strategies.

How Do I Prepare for the Quadruple Marker Test?

If you’re getting ready for a quadruple marker test, consider the following steps:

• Schedule an Appointment: Book your test at a diagnostic lab that offers the quadruple marker test. This will help you avoid delays on the day or enable home sample collection if available.
• Diet: You can eat normally before the test, as fasting is not necessary if the test is being conducted alone.
• Medications: Inform your clinician about all medicines and supplements you are taking. Certain medications could affect the results, so your doctor might recommend adjustments if needed.
• Bring a Support Person: Having a family member or friend with you can provide both physical and emotional support during the process.

What Is the Procedure for the Quadruple Marker Test?

Understanding the procedure can help alleviate any concerns you may have. Here’s what to expect during the test:

• Applying a Tourniquet: A tourniquet is placed around your arm to help make the veins more prominent.
• Cleaning the Injection Site: The area where the needle will be inserted is cleaned with a cotton swab soaked in 70% alcohol.
• Inserting the Needle: A small needle is inserted into a vein in your arm, and the necessary amount of blood is drawn and collected in a test tube.
• Removing the Needle: After the blood sample is taken, the needle is withdrawn, and a plaster is applied to the puncture site to help prevent infection.
• Laboratory Processing: The blood sample is then sent to a laboratory for further analysis and testing.

Factors That Can Affect the Quadruple Marker Test Result

The quadruple marker test assesses the risk of birth defects, but various factors can influence the outcomes. These include:

1. Age: The mother's age can significantly impact the chances of certain chromosomal abnormalities.
2.  Medical History: Pre-existing medical conditions or complications from past pregnancies may affect the results.
3.  Family History: A family background of genetic disorders or birth defects can influence risk assessments.
4. Baby’s Gestational Age: The timing of the test during the pregnancy can affect the accuracy of the results.
5. Maternal Weight: The mother’s weight may also influence the interpretation of the test results.

Understanding the Quadruple Marker Test Results

The quadruple marker test is an important screening tool that assesses the risk of specific chromosomal abnormalities and neural tube defects in the developing foetus. Results are typically presented as odds, such as "1 in 250" or "1 in 1,000," which reflect the likelihood of the foetus having conditions like Down's syndrome or a neural tube defect.

It’s essential to understand that this test serves as a screening measure rather than a definitive diagnostic tool. While it can identify pregnancies at higher risk for certain conditions, it cannot confirm the presence of any abnormalities. A positive result suggests that further testing may be warranted to gain more clarity.

When interpreting the results, a normal outcome usually indicates a low risk of chromosomal abnormalities and typically does not require additional testing. In fact, the majority of pregnancies with normal results (over 98%) suggest a healthy baby and a straightforward delivery. However, a normal result does not completely rule out the possibility of chromosomal issues, single-gene disorders, or certain birth defects.

Conversely, an abnormal result signals a heightened risk of chromosomal abnormalities or other fetal issues, prompting further investigation. Your healthcare provider may recommend more conclusive tests, such as:

• Amniocentesis: To detect chromosomal defects and potential infections in the foetus.
• Tests for Specific Birth Defects: To identify or rule out conditions like Down's syndrome.
• Genetic Counselling: To provide insights into potential genetic risks.
• Ultrasound: To examine the baby’s brain, spinal cord, kidneys, and heart.

It’s important to remember that results outside the normal range do not automatically indicate a problem. If you receive an abnormal result, your doctor may suggest additional testing to clarify any concerns and ensure proper care.

How to Avoid Birth Defects

To reduce the risk of chromosomal abnormalities and ensure a healthy pregnancy, it’s important to take preventive measures from the outset. While your doctor can offer personalised advice based on your specific health needs, here are some general guidelines that can be helpful for all expectant mothers:

• Maintain a Balanced Diet: Focus on a diverse range of vitamins and minerals essential for your baby’s development. Your dietary choices have a direct impact on the foetus, so aim to provide all necessary nutrients while minimising processed foods.
• Stop Smoking and Drinking Alcohol: Both of these habits are associated with an increased risk of various genetic conditions. As cultural shifts occur, the prevalence of genetic abnormalities has also risen.
• Plan Your Pregnancy Wisely: If you have chronic conditions like diabetes, careful planning is crucial. Uncontrolled blood sugar levels or other health issues can adversely affect the foetus and lead to potential abnormalities.

These tips can help lower the risk of congenital disabilities, but it’s vital to consult with your doctor for tailored advice on managing your pregnancy. Each pregnancy is different, and personalised care is essential for the best health outcomes for you and your baby.

Conclusion

The quadruple marker test is a vital screening tool in prenatal care, helping to evaluate the risk of chromosomal abnormalities and certain birth defects. While normal results can offer reassurance, they do not entirely rule out risks, and abnormal results suggest the need for further investigation without providing a definitive diagnosis. Expectant parents should consider the test as part of a broader prenatal evaluation and maintain clear communication with healthcare professionals to understand the findings and explore potential next steps, enabling them to make informed choices about their pregnancy and their baby's well-being.

Don’t delay—schedule your quadruple marker test today and take a proactive step towards better health for your baby. By staying informed and vigilant, you can address potential health concerns early and enjoy a healthier future.