Double Marker Test: What it is and What Happens During it?
When you’re in the last trimester of your pregnancy, a million questions must pop up about the foetus. And while the gender of your unborn child and other intricate details regarding your pregnancy will remain a mystery, when it concerns your OB-GYN, they may conduct tests to help you prepare for the arrival of your little bundle of joy.
The double marker pregnancy test involves taking a sample of your blood for further analysis to help detect abnormalities in the foetus.
Double Marker Test in Pregnancy
The first-trimester screening includes the double marker test, often known as maternal serum screening. While it does not constitute a conclusive scientific examination, it can report the likelihood of chromosomal abnormalities. This test is predictive rather than diagnostic.
The levels of beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A) in the blood are measured (PAPP-A).
Feminine foetuses, on average, have 22 pairs of XX chromosomes, whereas male foetuses have 22 pairs of XY chromosomes. Trisomy is one of the many chromosomal abnormalities resulting from having an additional set of chromosomes. Having an extra copy of chromosome 21 causes Down syndrome, also known as trisomy 21. Another common chromosomal abnormality includes having an extra copy of either chromosome 18 (which causes Edward's syndrome) or chromosome 13 (which causes Patau's syndrome).
There is some evidence that hCG and PAPP-A levels are atypical in chromosomally-defective pregnancies.
Blood levels are only part of the equation, though. Nuchal translucency (NT) scans are ultrasounds that look at the transparent tissue at the back of your baby's neck instead of just the blood.
When Is the Double Marker Test in Pregnancy Required?
This test is often recommended during the first trimester to prevent difficulties before or after delivery. Beta-human chorionic gonadotropin (free beta-hCG) and pregnancy-related proteins are measured in the blood throughout the screening process (PAPP-A).
The window of opportunity for such screening is typically narrow. The doctor or nurse on call may know best. The surgery is typically performed between the 11th and 14th week of pregnancy.
Why is a Double Marker Test in Pregnancy Conducted?
Screening with a double marker test and an NT scan in the first trimester is recommended but not required.
However, suppose you're over 35 or have a potentially heightened risk of chromosomal abnormalities, such as a family history of specific disorders. In that case, you should consider getting screened.
Remember that this result can only tell you if you're at a higher risk for trisomies, not why. Your baby's abnormality status won't be determined with any certainty.
When you decide whether or not to have a double marker test, it's important to consider what the outcomes may imply for you down the road. What if the results are higher than normal? Would you be prepared to get tested more thoroughly? If you knew about potential irregularities, how would that make you feel? When it comes to pregnancy care, would your approach change based on the findings?
There are no definitively correct responses to your inquiries because they depend entirely on your circumstances and medical history.
How Is a Double Marker Test in Pregnancy Conducted?
A blood sample and an ultra-sound examination constitute a double marker test. The free beta hCG (human chorionic gonadotropin) and PAPP-A are the two markers analysed in the double marker test (pregnancy-associated plasma protein A).
The placenta secretes a glycoprotein hormone called free beta-hCG in pregnant women. A high value is associated with an increased risk of trisomy 18 and Down syndrome.
PAPP-A plasma protein is a crucial component of the body. A high risk of Down syndrome is associated with low plasma protein levels. The test results are screened as positive, high-risk, and negative.
What is the Cost of a Double Marker Test in India?
The cost of a double marker test will vary based on factors such as your location and health insurance. Although you're under no obligation to take this test, your health insurance plan could pay for it if you do.
Contact your insurance company to learn more about your coverage and pre-authorization requirements. If you do not have health insurance, you may still find out about the price and any available payment options or rebates by calling the hospital or laboratory directly.
You'll need to pay for this and the NT scan if you want a thorough first-trimester screening, as they are typically performed together. Double marker test prices range between Rs. 2,500 and Rs. 3,500, depending on where you live and which hospital you choose.
What to Expect in Test Results?
A basic blood test is required for the double marker test. The lab will need the order that your doctor has written for you. Unless otherwise indicated, you can eat and drink normally before your visit because this is not a fasting test.
Turnaround times in laboratories might vary. The typical turnaround time for test results is between 3 and 7 days. You might want to find out if the clinic will call you with the findings or if you need to contact them directly.
Frequently Asked Questions
Q: What if The Double Marker Test is Positive?
A: The likelihood of a kid having any given condition may be estimated using these ratios. Suppose the double marker test turns out to be positive. In that case, the doctor may suggest performing additional diagnostic procedures such as amniocentesis or chorionic villus collection to determine the source of the issue.
Q: What is Considered a Normal Range for a Double Marker Test in Pregnancy?
A: A normal range is 25,700 to 2,88,000 mIU per mL on a double marker test.
Q: How Accurate is a Dual Marker Test?
A: A dual marker test is just preparatory. Just about half of normal sensitivity is required. In half of the cases, the test may provide an inaccurate result. An amniocentesis test will be needed for confirmation.