Double Marker Test

Pregnancy can be an exciting journey for expecting parents. However, this is also a time when both the mother and the child might be prone to certain health risks. To battle these risks, medical professionals have developed a variety of screening and diagnostic tests.

The Double Marker test, or the dual marker test, is one such test that has emerged as a valuable tool in assessing the risk of genetic defects in the foetus. Keep reading this comprehensive overview of the double marker test to learn more about its purpose, procedure, and the insights it offers expectant parents and medical professionals.

Understanding the double marker test

The double-marker test, or maternal serum screening, is a prenatal screening test. This test is an early assessment tool that can report any possible Chromosomal Abnormalities in the developing foetus. The dual-marker blood test is usually carried out during the first trimester of pregnancy.

The dual marker test combines the results of two distinct blood markers human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein-A (PAPP-A). These markers are present in the mother’s blood and can provide valuable information about the potential risk of chromosomal abnormalities, particularly Down syndrome and Edwards syndrome.

The dual-marker blood test is generally recommended if the expectant mother is over the age of 35 or if the couple has a history of congenital disabilities in their family.

However, it is essential to note that the double marker test is not a diagnostic test but a screening test. This means that the test can only provide an estimation of the risk. Based on the test results, expectant parents can decide whether to go forward with a diagnostic procedure.

Procedure and results

The double marker test is a straightforward yet informative screening test to assess the risk of foetal chromosomal abnormalities. This procedure can be carried out anywhere between the 8th and 14th week of pregnancy.

The expectant mother’s blood samples are collected and checked for hCG and PAPP-A levels in this test. hCG is a glycoprotein hormone secreted by the placenta during pregnancy. A high level of this hormone can mean an increased risk of Down syndrome in the foetus. In contrast, PAPP-A is a plasma protein that is a crucial component of our body. If this plasma protein is detected at low levels, then that also indicates an increased risk for Down syndrome.

Sometimes, an NT (nuchal translucency) scan can accompany the dual-marker blood test. During an NT scan, the healthcare professional uses soundwaves to calculate the size of the clear area on the back of the foetus’s neck. The findings of the NT scan and blood samples will help your doctor provide an accurate analysis of the baby’s risk of chromosomal abnormalities.

Double-marker test reports can provide three results: low-risk, moderate-risk, and high-risk. If your test results fall in the low-risk category, that suggests a low probability of a chromosomal abnormality.

However, if the results fall in the moderate-risk or high-risk category, you should consider undergoing further diagnostic tests. The non-invasive prenatal test (NIPT) is often recommended to confirm the chances of any genetic condition.

Significance of the dual marker test

While the double marker test in pregnancy is not an absolute requirement, it is a recommended procedure with its own set of benefits.

Early detection 

One of the primary advantages of the double marker test is its early timing. Typically, this test is carried out between the 11th and 13th weeks of pregnancy. Detecting potential chromosomal abnormalities in these early stages provides more time for expectant parents to make an informed decision about their pregnancy journey.

Informed decision-making 

The test results empower parents with valuable information. They can choose to undergo additional diagnostic tests for confirmation or opt for genetic counseling to understand the implications of the results thoroughly. An informed decision-making process ensures parents make choices aligned with their beliefs and values.

Reduced anxiety 

Pregnancy can be an intense period. Uncertainty about the baby’s health can add stress. The dual-marker test can be used to offer reassurance to parents regarding their baby’s health. If the results indicate a low risk of chromosomal abnormalities, parents can take a sigh of relief and focus on a healthy pregnancy journey.

Medical management  

The dual marker test in pregnancy can provide tremendous support in medical management. If the test results find an increased risk of chromosomal abnormality, healthcare professionals can take extra care during the pregnancy. They will closely monitor the pregnancy and offer necessary medical interventions or plan for specialized care during the later stages of pregnancy. Early detection allows for proactive measures to ensure the well-being of both mother and child.

Limitations

Although the double-marker test provides valuable information, it is crucial to acknowledge its limitations. The test is a screening tool, not a diagnosis. A high-risk result does not guarantee the presence of a chromosomal abnormality. It prompts further investigations for confirmation.

Additionally, false-positive and false-negative results are also possible. This is why confirmatory diagnostic tests are recommended for high-risk cases.

A dual marker in pregnancy is a helpful screening test that can provide insights into potential chromosomal abnormalities in the early stages of pregnancy. It empowers parents to make informed decisions about their journey if undertaken on time.

However, it’s essential to understand that the results are indicative and not definitive. Consulting with healthcare providers, seeking genetic counselling, and considering additional diagnostic tests are integral to navigating the path ahead.