One of the most important “maternal blood screening tests” is the quad screen test.
Four specific substances will be tested under this test.
They include: hCG (Human chorionic gonadotrophin), AFP (Alpha fetoprotein), inhibin-A and Estriol.
- hCG is a hormone that is created within the placenta.
- AFP is produced by the fetus.
- Inhibin-A is a protein which is produced by the ovaries and placenta.
- Estriol is an estrogen produced by the placenta and also the fetus.
This test is very similar to the triple screen test. The only difference is, in the quad screen test, the possibility of recognizing the risk of Down syndrome is higher with the evaluation of inhibin-A levels.
How is the quad screen test performed?
This test includes collecting a blood sample from the mother, which lasts for 5-10 minutes. This sample of blood is then tested in the laboratory and the results will be displayed within a few days.
During the test process, you will experience slight discomfort. Instead of this, there are no known dangerous consequences or risks associated with quad screen test.
Usually, you will need to undergo this test procedure between the 16th-18th weeks of pregnancy. Most pregnant women are eligible for this test procedure, but women who should undergo this test procedure particularly include:
- Pregnancy after 35 years of age
- Suffering with diabetes and receiving regular dosage of insulin
- Exposed to high levels of radiation
- Having a family record of common birth defects
- Suffering from any form of viral infection during pregnancy
- Taken harmful drugs or medications during the pregnancy period
Benefits of quad screen test:
This test is useful to measure high or low AFP levels, high levels of inhibin-A, and abnormal levels of estriol and hCG. These results are included with your age and background to identify the possibilities for dangerous genetic disorders.
If the test confirms high AFP levels, then your baby is at a risk of neural tube defects like anencephaly or spina bifida. The most common cause for high AFP levels is incorrect dating of pregnancy.
Abnormal hCG and estriol levels and low AFP levels indicate that your baby has the possibility to develop Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18) or various other chromosomal abnormalities.
Remember that the quad screen test is a type of screening method, but not a diagnostic method. This method only shows whether you are carrying at a risk of genetic disorders.
If the test shows abnormal results, then your practitioner recommends for high definition ultrasound. However, if the test gives abnormal outcomes, then a more invasive method called amniocentesis test is recommended. However, before undergoing the test procedure once, discuss it with your doctor.