Dual Marker Test in Madurai

• This test is done in pregnant women to identify serious birth defects early in the pregnancy
• Also called prenatal screening
• Dual or Double marker test in first trimester, identifies pregnancies that have a high risk of babies having the following chromosomal abnormalities: Trisomy 21 (Down’s syndrome), Combined Trisomy 13 (Patau syndrome)/ Trisomy 18, (Edwards syndrome)
• This test is NOT a diagnostic test; it only identifies the risk of the baby being affected. Your doctor will order follow up and confirmatory test when the results of dual marker tests indicate a risk

For pregnant women, to check if the baby is at a risk of having chromosomal disorders such as Down syndrome (trisomy 21) or Edwards syndrome (trisomy 18). Dual Market in the firsr trimester is done between the 11th and the 14th week of pregnancy. A dual marker is recommended for all pregnant women. Below risk factors increase the chance of birth defects and hence under these risk factors, it is important to take the dual marker test

• age 35 or older pregnant females
• family history of birth defects
• previous child born with a birth defect
• History of diabetes, dependence on insulin in type 1 diabetes

Dual or Double Marker Test (with or without NT)– This includes

• Free β hCG (Free Beta Human Chorionic Gonadotropin)
• PAPP - A (Pregnancy Associated Plasma Protein – A) Free β hCG (Free Beta Human Chorionic Gonadotropin) Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone normally produced by placenta during pregnancy
• Very early in pregnancy, it is the substance used in pregnancy tests and urine pregnancy kits
• The hormone consists of two subunits – alpha and beta chain subunits
• There is a significant increase in the level for free beta hCG subunit in Trisomy 21 cases; the levels are lower in Trisomy 18 cases PAPP - A (Pregnancy Associated Plasma Protein – A): As the name suggests, is an important pregnancy protein
• PAPPA is synthesised in the placenta. The levels in pregnancy are 150 times higher than those in non-pregnant states
• If Trisomy 21 or Trisomy 18 is present, then the PAPPA levels are reduced in the first trimester and this gives a risk profiling of the foetus