The development of a fetus can be disrupted by numerous chromosomal abnormalities, which can result in too many issues for the growing fetus. These abnormalities may be caused by an imbalance in the number of chromosomes, structural defects in the chromosomes, or an improper amount of genetic material in a specific chromosome. These abnormalities can lead to chromosomal disorders, congenital malformations, and even miscarriages. Such fetal abnormalities can result in postnatal malformations in the newborn if they are not discovered, which is why the double marker or dual marker test is used to detect them.
What is a Double Marker Test?
A predictive test that finds chromosomal abnormalities in a pregnant woman’s fetus is the double marker test, also called the dual marker blood test or maternal serum screening. Beta-human chorionic gonadotropin (hCG), a hormone linked to pregnancy, and pregnancy-associated plasma protein A (PAPP-A) are the two markers that are measured in the blood erythrocytes during the test.
There is a strong correlation between chromosomal abnormalities and altered levels of these markers. Physicians typically recommend the double marker test during the first trimester of pregnancy to identify any anomalies early on and avert a number of postpartum health issues for the child.
Importance of the Double Marker Test
Is the double marker test necessary? Yes, it is important because early identification of chromosomal abnormalities in the developing fetus can be aided by the dual marker test. A female fetus has 22 pairs of XX chromosomes, and a male fetus has 22 pairs of XY chromosomes during a normal pregnancy. Rarely, though, an extra chromosome may exist in part or all of the body’s cells, resulting in trisomy, a genetic disorder.
These fetuses may experience intellectual and developmental problems because they have three copies of that chromosome rather than two. Down syndrome, Edwards syndrome, and Patau’s syndrome are the defects brought on by trisomy. Therefore, the dual marker test can assist in protecting the mother and her unborn child by identifying chromosomal abnormalities.
How the Double Marker Test Works
A double marker test procedure consists of an ultrasound examination and a blood sample. The dual marker test analyses two markers: PAPP-A (pregnancy-associated plasma protein A) and free beta hCG (human chorionic gonadotropin). In pregnant women, the placenta secretes a glycoprotein hormone known as free beta-hCG. An elevated value is linked to a higher incidence of Down syndrome and trisomy 18. The plasma protein PAPP-A is an essential part of the body. Low plasma protein levels are linked to an increased risk of Down syndrome. Test findings are filtered as negative, high-risk, and affirmative.
Conditions Detected by the Double Marker Test
The double marker test assists in identifying the likelihood that the fetus will experience mental or neurological problems. It identifies Trisomy 21, Trisomy 18, and Trisomy 13, which cause mental and physical difficulties in the infant, as well as Down syndrome.
Benefits of the Double Marker Test
- The dual marker test not only identifies flaws in the developing fetus but also gives parents-to-be the knowledge they need to make educated decisions about their pregnancy.
- Since the double marker test is non-invasive, there is no risk to the fetus or the expectant mother. It’s a straightforward technique for identifying certain chromosome defects in a developing baby.
- This procedure evaluates if the mother’s health could be harmed by the pregnancy and assists in identifying risk factors associated with it.
- Additionally, the dual marker test is reasonably priced. It is available to a larger proportion of women who might not have access to more costly diagnostic tests and is an affordable way to identify chromosomal abnormalities during pregnancy.
- For some women, knowing the outcome of a double marker test gives them peace of mind and aids in their preparation for the birth of their child.
Limitations and Considerations
There are certain limitations and considerations with the Double Marker Test. It is not a diagnostic test, but it does assist in screening for chromosomal abnormalities such as Down syndrome. It can occasionally produce false positives or negatives, which can cause needless anxiety or false reassurance. It might not identify every possible fetal problem; it only detects specific disorders. Furthermore, it works best when completed within the suggested window of time, which is normally between weeks 11 and 14 of pregnancy. For more precise confirmation, women with higher risks or abnormal results could require additional diagnostic testing.
When to Consider a Double Marker Test?
The dual marker test is typically conducted as part of a comprehensive screening panel between weeks 8 and 14. The best period for a combined risk assessment is between weeks 11 and 13, which is when the blood sample for this test is taken.
Given their increased risk of developing chromosomal abnormalities, which could result in chromosomal deformities in the fetus, doctors advise this test for women over 35 or those with a family history of birth defects.
What to do After the Double Marker Test?
It’s crucial to talk to your doctor about the double marker test results. Although it’s not a certainty, low-risk results usually indicate a decreased likelihood of chromosomal abnormalities. Your doctor can suggest additional diagnostic procedures, including amniocentesis or chorionic villus sampling (CVS), to confirm the results if they indicate an elevated risk. Whatever the result, the test can give you important information to help you plan the rest of your pregnancy. It’s critical to remain educated and to get expert counsel for any queries or worries.
Conclusion
To find anomalies early in pregnancy, a dual marker test is highly recommended. A double marker test report can offer extra information that helps with pregnancy development and management, but it is not required. To get additional information, you can visit the Oasis Fertility Clinic near you. You can also engage with us using the live chat facility or contact us at 1800-3001-1000 for prompt assistance.
FAQs on Double Marker Test
What if a dual marker test is positive?
Although it does not validate a diagnosis, a positive result suggests a higher likelihood of chromosomal abnormalities. Other diagnostic procedures like amniocentesis or CVS can be suggested for confirmation.
What is the normal range of a double marker test?
Maternal age and gestational age are among the variables that determine the normal range of the double marker test; nonetheless, if the findings indicate a risk ratio of 1 in 250 or greater, the chance of Down syndrome is generally regarded as low.
What is the difference between an NT scan and a double marker test?
The double marker test is a blood test that evaluates specific hormone levels to determine chromosomal risk, whereas the NT scan is an ultrasound that detects the nuchal translucency (fluid at the back of the baby’s neck).
Which is the best week to take the dual marker test?
The dual marker test should preferably be taken during the first-trimester screening window, which is between weeks 11 and 14 of pregnancy.