Triple Marker Test - Prenatal Screening for Birth Defects
What is Triple Marker?
A Triple marker test is a blood test conducted during pregnancy. It is not a simple diagnostic test, and it also involves a Triple marker screening. It does not provide a diagnosis; rather it simply indicates any potential genetic abnormalities in the baby. Further tests and doctor consultations are required to diagnose the suspected abnormality. Screening means the triple marker test report also factors in the expecting women’s age, weight, ethnicity, pre-existing diseases, type of pregnancy (multiple, twins) etc.
The exam measures the levels of three important substances in the placenta:
- Alpha-fetoprotein (AFP)
- Human chorionic gonadotropin (HCG)
- Estriol
Triple Marker Details
So, what is triple marker test? A triple marker test is a prenatal test to examine the likelihood of birth/genetic/chromosomal defects in the to-be-born baby. The Triple marker test procedure is advisable for all pregnant women, especially if they report:
- Family history of genetic problems.
- 35 years of age or more.
- Pre-natal medications/drugs with side effects.
- Diabetic and insulin use.
- Pre-natal viral infection.
- High exposure to radiation.
The triple marker blood test is conducted in the second trimester. It examines the serum levels of three hormones:
- Alpha-fetoprotein (AFP)
- Unconjugated estriol
- Human chorionic gonadotropin (beta-hCG)
Triple marker down syndrome is most commonly used to detect Down Syndrome (a chromosomal disorder) between 15 to 18 gestation weeks.
How Is the Test Performed?
The triple test procedure is the same as the procedures involved in any other blood test. Here is how your doctor or technician will perform this test.
- Step 1: First, the technician will ask you to extend your arm and make a fist. This will help him find your vein.
- Step 2: Then the doctor will place a strap around the arm and secure this point firmly.
- Step 3: Next, the technician will clean the area with an antibacterial and antiseptic wipe.
- Step 4: Then a needle will be inserted attached to a vial used for blood storage.
- Step 5: Once the vial is full, the technician will pull out the vial, clean the area with another antiseptic and antibacterial swab.
- Step 6: The blood sample will then be sent for evaluation to a lab where the biochemist will evaluate the sample.
- Step 7: The results will then be put in software which will then be sent to the doctor. The doctor will then share the result with you.
Reasons to Have a Triple Marker Test During Pregnancy
- The triple test helps identify Trisomy 18 (Edward’s Syndrome) during pregnancy.
- The Trisomy test helps identify whether the woman is expecting two or more babies.
- The test also detects other abnormalities that could help the doctor proceed further with a diagnosis.
- By conducting this test early on in pregnancy, neural tube defects and other birth defects can be detected.
- This test can help identify if the baby is at the risk of developing Down syndrome.
Interpretation of the Test Results
The results of the triple marker tests show the likelihood of a baby having a genetic disorder. The results, however, depend on the following factors:
- Age of the pregnant woman
- Ethnicity
- Pregnant woman’s weight
- Whether she is expecting a single child or multiple babies
- How far along she is in her pregnancy
Once you undergo this test, your OB/GYN will analyze your triple marker test report and let you know whether the results are negative or positive. Your doctor may also suggest more tests if the results of this test are false positive or she does not see a normal value for the triple marker test.
