What is All of the following antenatal screening tools indicate increased risk of Down syndrome EXCEPT? and explain in detail?
Antenatal Screening for Down's Syndrome USG - Nuchal Thickness > 3 mm 11 - 14 weeks of gestation - Absence of nasal bones - Sho femur - Duodenal Atresia Biochemical Tests 1st Trimester - b-HCG, PAPP-A (Pregnancy associated Plasma Protein - A) (Dual Test) 2nd Trimester QTriple Test - AFP (a-Fetoprotein) + b-hCG + Unconjugated Estirol Quadruple Test - Triple Test + Inhibin Mnemonic HI High (||): HCG & Inhibin levels increase in Down syndrome Integrated Test - Best test screening Down's syndrome (Sensitivity - 95-97%) - Maternal age + 1st Trimester (NT + PAPP-A) + Quadruple Test (2nd Trimester) Confirmatory test for antenatal Dx of Down syndrome - Fetal karyotyping, for which genetic material may be obtained by- - Chorionic Villous Sampling (CVS) - Amniocentesis - Cordocentesis (Percutaneous Umbilical cord Blood sampling) But these are invasive procedures that carry risk of aboion.