<prompt> Which of the following is useful in first trimester screening for Downs syndrome?InhibinEstradiolPAPP-AAcetylcholinesterase  <response>: Down;s syndromeScreeningUSG markersMaternal age - Age 35, the screening test is offered.Biochemical testsUltrasonographyFirst-trimester screening for Down;s syndromePAPP-A. hCG biochemical testsNT nuchal translucency USGPAPP-A pregnancy-associated plasma protein-decreases in Down;s syndromeSerum beta hCG - elevated in Down;s syndromeNuchal translucency increases in aneuploid fetus in first-trimester: 3.5 mm is significant done at 11-14 weeksSensitivity of combined NT thickness and 1st trimesterbiochemical tests are 90.Second-trimester screening for Down;s syndromeTriple test and quadruple tests are done in second trimesterat 15-20 weeksTriple test: hCG, AFP, unconjugated estriolQuadruple test: Triple test inhibinNuchal fold thickeningMild renal pelvis dilatationEchogenic intracardiac focusEchogenic bowelSho femurSho humerusRefer: Mudaliar and Menon;s Clinical Obstetrics, 11th edition, pg no: 466 