Double Marker Test and What It Means During Pregnancies?

Pregnancies are fragile and it is better if you remove the mysterious suspicion of possible health complications for both the mother and the baby. One such modern diagnostic tool is the double marker test or the dual marker test that involves the analysis of blood for markers of specific chromosomal abnormalities. Modern medicine has achieved a huge feat with this test since it rules out the avoidable mishaps in pregnancy, thereby making the baby safe and the mothers at ease.

What is the double marker test?

Medically known as the maternal serum screening, the double marker test is a predictive test performed to figure out the probability of chromosomal abnormalities. This test is a part of a more comprehensive test, the first-trimester screening. Since this test does not produce definitive results, it is classified as a predictive test. To be precise, this test checks for blood levels of pregnancy-associated plasma protein-A and the free beta-human chorionic gonadotropin. In the case of a typical pregnancy, female fetuses should possess 22 pairs of XX chromosomes whereas male fetuses should possess 22 pairs of XY chromosomes.

double marker test procedure

Benefits of the double marker test

The primary objective of this test is to successfully detect chromosomal abnormalities in the fetus. There are more other reasons why doctors suggest this test be conducted for better safety and precaution. Some of those other reasons are listed below:

  • It is quite a reliable test, and on most occasions, it correctly detects any possible abnormalities or issues with accuracy.
  • If the test results turn out to be positive that is, it detects the chromosomal abnormalities, further diagnostic processes and measures can be commenced to remedy it. Hence, this test helps recognize and fix the anomalies pre-emptively.
  • Doctors generally recommend this test to find out if the baby has possible Edward’s syndrome or Down’s syndrome before advising for a more advanced and invasive test. The double marker test procedure enables the doctor to safely identify anomalies and recommend the required course of treatment before it becomes too late.
  • If the test results turn out to be positive, along with the diagnosis of a neurological condition, the parents can choose whether they would like to terminate the pregnancy sans complications, in the initial stages of pregnancy.

What are the standard results produced in the test?

The test could produce results that indicate a low, moderate, or high risk.

  • A negative screen or low risk is considered as normal and diagnoses that your baby is far from the risk of developing chromosomal abnormality.
  • If the results turn out to be negative or normal, other risk factors such as family history, advanced age and more can be determined through further testing as per your doctor’s recommendations.
  • Low risk does not assure that your baby will possess zero abnormalities. It simply diagnoses that the chances of an abnormal fetus are very remote.

How are the test results interpreted?

The double marker test procedure can produce either a screen positive or a screen negative. These results of the test, apart from blood samples, also depend on the age of the fetus as determined through the ultrasound as well as the age of the mother. All these factors produce a result in a ratio format. A ratio between 1:10 and 1:250 is a screen positive result and involves a high risk of abnormalities. A ratio of 1:1000 or more is a screen negative result and indicates lower risk.

If the test turns out to be a screen positive, your doctor may recommend the further diagnosis, primarily chorionic villus sampling or amniocentesis based on the resultant ratios.

What are the normal values of the test?

The results from the double marker test procedure are obtained in the form of ratios. A ratio of 1:10 to 1:250 is termed screen positive, involving a high risk of chromosomal abnormalities. On the other hand, a ratio of 1:1000 or higher is termed as a screen negative result, thereby indicating a low risk of the same. Further diagnostics may amniocentesis or chorionic villus sampling depending on the various factors considered which affect the test results.

A Final Word

If you are unsure whether you should avail of the dual marker test, you can assess by weighing the several advantages of the double marker test along with the first-trimester screening. The information from a little research about the double marker test procedures might help you in deciding how you intend to manage your pregnancy. The test is a predictive test that simply ensures the fetus does not possess any chromosomal abnormalities.

Although subjecting to this test is a choice taken by the individual to be tested, women who are older than 35 years are strongly advised to avail this test since abnormalities tend to occur at this age. No matter what it is you decide to go with, a healthy pregnancy stems from utmost care and regular contact with your healthcare provider.

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