<prompt> Ideal time for doing quadruple test:-8-12 weeks11-15 weeks15-18 weeks18-22 weeks  <response>: Triple test : screening test Its a screening test for down syndrome trisomy 21 Done between 16 and 18 weeks of gestation It involves estimation of three hormones : hCG, AFP, UE3 To the triple test, if the level of a fouh marker dimeric inhibin alpha are added, the test is called as QUAD test or Quadruple test inhibin A 1st trimester 2nd trimester Screening test Nuchal tranaslucency - hCG PAPP-A Quad test tirple test Diagnostic test karyotyping Chronic villi sampling Amniocentesis 