Medical science has advanced, and so have the ways of tracking and caring for a pregnancy. Till just a decade ago, advanced-level tests weren’t available to ascertain every aspect of a fetus’ health. But today things have changed for the better.
While the start of a pregnancy can be confirmed with a simple home test, later on, there are a few critical tests that must be taken based on a doctor’s prescription. One of them is a double marker test. A Double-marker test can detect a baby’s health while inside the womb. Like many other tests or sonography, the double marker is not done in the regular course. It is ordered by a doctor if there are some markers in earlier blood tests.
What does a dual marker test indicate?
A Dual marker test is an indicator of genetic anomalies in the fetus. It points toward conditions like Down syndrome, Edward’s syndrome, and Patau’s syndrome.
- Down Syndrome – We have a total of 22 pairs of chromosomes. For a female, they are 22 pairs of XX chromosomes. Males have 22 pairs of XY chromosomes. Down syndrome is the presence of an extra copy of Chromosome 21 out of 22 chromosome pairs. Down syndrome can cause growth disorders.
- Edward’s syndrome – Edward’s Syndrome is the presence of an extra copy of Chromosome 18. It is also called Trisomy 18 and can cause mental retardation and birth defects.
- Patau’s syndrome – Patau’s syndrome is the presence of a copy of Chromosome 13. It is also known as Trisomy 13. It causes mental disorders, disorders of the heart, and other vital organs.
When is a dual marker test done?
A double-marker test is done in the first trimester of pregnancy, between weeks 10 and 14.
- High levels of Beta-hCG – Take the test when an earlier blood test shows high levels of free Beta-hCG. High levels of Beta-hCG indicate a risk of Down syndrome. The placenta produces Beta-hCG hormone during pregnancy. This hormone shows pregnancy during blood tests and home pregnancy tests, but too much Beta-hCG can be problematic. It is sometimes high in case of multiple pregnancies (twins or more).
- Age of the mother – When the age of the prospective mother is more than 35, doctors prescribe this test as a precaution. After the age of 35, risk factors increase, and this test can help rule those factors out.
- Levels of PAPP-A – PAPP-A is Pregnancy Associated Plasma Protein. It is essential during pregnancy, and low levels of PAPP-A call for a Double Marker test. A low level of this protein indicates Down syndrome, Edward syndrome, or Patau syndrome.
- Family History – If the patient’s family has a history of congenital disorders or diabetes, the doctor may prescribe a double-marker test.
Procedure and precaution of the test
The process is simple and is done through a blood test. A lab technician will draw blood from your veins. Tighten your fist with your thumb inside. The lab technician will tighten a band on your forearm, just above your elbow. Then, the technician will draw the blood. This process is short and is complete within minutes.
In terms of precautions, drinking sufficient water is advised. If you need to stop any medicine for the test, the doctor will inform you about the same.
Dual Marker test results
Test results are back in 3 days to a week.
The test result is given in terms of screen positive or screen negative. A screen positive means high risk, while a screen negative means low risk. A ratio up to 1:250 indicates a positive. Any score above it is negative. These ratios are pointers that 1 in 250 pregnancies had genetic anomalies. While 1:1000 points to one in thousand pregnancies having congenital conditions.
A positive marker can call for further tests of pregnancy, like NIPT. First-trimester ultrasound is done during the same time. The ultrasound shows a scan of NT (Nuchal Translucency). It is a transparent tissue at the back of the baby’s neck. If it is higher, then this may also call for further tests.
The doctor can determine the next steps based on the combined results of the ultrasound and Double-marker test.
All the tests are done to take better care of patients. They can either be specially prescribed tests or routine tests. Either way, it is better to do the tests when prescribed. Sometimes, patients avoid or delay tests in anticipation of unwanted results. Whatever the test result, you will know the actual condition of the health of your child. In case of non-desirable results, your doctor will support you by prescribing a further course of action. In the case of labs, always choose reputed ones to get accurate and timely results.