Introduction:About one in 800 babies is born with Down syndrome, caused by an extra copy of chromosome 21 (trisomy 21).
The maternal Markers tests are blood tests available to pregnant women to help determine the risk of Down syndrome (trisomy 21), Edward syndrome (trisomy 18) or neural tube defects in their unborn child.
These test are used to classify a patient as either high-risk or low-risk for chromosomal abnormalities (and neural tube defects).
1. DOUBLE MARKER: This is first trimester risk assessment.
2. TRIPLE MARKER: This is 2nd trimester risk assessment.
3. Quadruple marker: This is also 2nd trimester risk assessment.Want to Buy Something Interesting?
Advantage of Quadruple marker:
· Enhanced accuracy with Prisca 5 Software using MoM(Multiple of Medians) of Indian data base
· 2. DIA levels are 2 fold higher in Down syndrome pregnancies
· Easy to Perform rapid diagnosis, cost effective, no risk to foetus
· Increase detection rate by 15% and reduces false positivity rates by 40%
4. Standard integrated marker: This is combination of double marker and quadruple marker
Features of Standard integrated marker test:
· 1st trimester test results are released post evaluation of 2nd trimester quadruple test
· Detection rate is 86% and false positive is much lower(1% vis a vis 5%) than triple test
5. Sequential Integrated marker test: This is combination of Double marker + Quadruple marker or CVS by FISH. Double Marker Positive cases are offered CVS or Amniocentesis Chromosome analysis, whereas Double Marker Negative are offered second trimester Serum test. Phase II (2nd Trimester): 15-22 Weeks. (AFP, HCG, E3UN & DIA). Final risk assessment incorporates first and second trimester results.
Features of Sequential Integrated Marker test:
1. 1st trimester test result determines 2nd trimester test
· Low risk: Quadruple test
· High risk: CVS by FISH
2. Detection rate is 90%.
PAPP-A: PREGNENCY ASSOCIATED PLASMA PROTEIN – A
HCG: HUMAN CHORIONIC GONADOTROPIN1. https://www.betterhealth.vic.gov.au/health/.../pregnancy-tests-maternal-serum-screening