What is the quad marker screening test? 

The quad marker screening test (quad screen) is a blood test that provides information about whether there is an increased risk for certain birth defects in the baby. 

What does the quad marker screening test screens for?

The quad screen is a simple blood test that screens pregnancies for Down syndrome, trisomy 18 and neural tube defects. 

Is there any risk of quad marker screening test?

No known risk to the mother or developing baby. 

How is the quad marker screening test performed? 

The quad marker screening test involves drawing blood from the mother. 

The blood sample is then sent to the laboratory for testing. 

The results usually take a few days to receive. 

When is the quad marker screening test performed?

Between the 15th and 20th week of pregnancy. 

All pregnant women should be offered the quad marker screening test, but it is recommended for women who: 

1.    Have a family history of birth defects

2.    Are 35 years or older

3.    Used possible harmful medications or drugs during pregnancy

4.    Have diabetes and use insulin

5.    Had a viral infection during pregnancy

6.    Have been exposed to high levels of radiation 

What does the Quad Marker Screening Test look for?

1.    AFP 

2.    hCG


4.    Inhibin-A 

The results are combined with the mother’s age, weight, ethnicity, and gestation of pregnancy in order to assess probabilities of potential genetic disorders. 

What do the Quad Marker Screening Test results mean?

  1. It is screening test and not a diagnostic test. 
  2. This test only notes that a mother is at possible risk of carrying a baby with a genetic disorder. 
  3. The test is known to have a high percentage of false-positive results. 

What is meaning of ABNORMAL test results? 

Abnormal test results warrant additional testing for making a diagnosis.

Second quad screen followed by a high definition ultrasound. 

If the testing still maintains abnormal results, a more invasive procedure like amniocentesis may be performed. 

How accurate is the quad screen? 

When an abnormality exists, the quad screen can detect an increased risk for approximately 85 percent of neural tube defect cases, about 80 percent of Down syndrome cases and 80 percent of trisomy 18 cases. 

What is meaning of negative screen?

A negative screen means it is unlikely the fetus has Down syndrome, trisomy 18, or an NTD. 

But a negative screen does not guarantee the birth of a healthy baby. 

The screening test only screens for Down syndrome, trisomy 18, and NTDs; it is not a diagnostic test. 

What is meaning of false-positive result screen?

A false-positive result can cause stress and lead to unnecessary testing (such as an amniocentesis). 

If your test results are abnormal, your doctor may use a fetal ultrasound to make sure of your baby's age. A false positive may be more likely with the triple screening than the quad screening. 

How diagnosis of chromosomal abnormalities is confirmed?

The diagnostic procedures available for prenatal diagnosis of chromosomal abnormalities are CHORIONIC VILLUS SAMPLING (CVS) and AMNIOCENTESIS.

These procedures, which carry up to a 1% risk of causing a spontaneous termination (miscarriage), 

are nearly 100% accurate in diagnosis.