It is important to remember that this is a screening test, not a diagnostic test.
If the test shows there might be a problem, another test must be done to confirm or
rule out a diagnosis.
Why Is the Multiple Marker Test Done?
The multiple marker test is done between weeks 15 and 20 of a woman's pregnancy
to screen for neural tube defects (such as spina
bifida) and chromosomal disorders (such as Down
syndrome and trisomy 18).
Depending on the number of things measured, the test also is called:
a "triple screen" or "triple marker" because it looks at the levels of a protein,
alpha-fetoprotein (AFP), and two pregnancy hormones, estriol and human chorionic gonadotropin
a "quadruple screen" ("quad screen") or "quadruple marker" ("quad marker") when
the level of another substance — inhibin-A — is also measured
This screening calculates a woman's individual risk based on the levels of the
three (or more) substances, as well as:
whether she has diabetes requiring insulin treatment
The greater number of markers increases the accuracy of the multiple marker test
and better identifies the possibility of a problem. In some cases, doctors will combine
the results of this test with results from the first
trimester screen to get an even better idea of a baby's risk for Down syndrome
and neural tube defects.
Should I Have the Multiple Marker Test?
All pregnant women are offered some form of this test. Some health care providers
include more parts of it than others.
Remember that this is a screening test, not a diagnostic test. It's also not foolproof
— a problem might not be detected, and some women with abnormal levels are found
to be carrying a healthy baby. Further testing is recommended to confirm a positive
When Is the Multiple Marker Test Done?
The blood tests are typically done between 15 and 20 weeks.
What Happens During the Multiple Marker Test?
Blood is drawn from the mother.
When Are the Results Available?
Test results usually are ready within a week, but can take up to 2 weeks.