In the first trimester screening for Down syndrome which of the following test is to be done?: (A) Beta HCG, PAPPA, (B) MSAFP, PAPPA, (C) Inhibin, PAPPA, (D) Unconjugated Estriol, PAPPAs
Answer is A. a. Beta HCG, PAPPA(Ref: Nelson's 20/e p 610-615)Methods for Antenatal Screening for Down Syndrome - In 1st Trimester pg 79Screening methodDetection rateMaternal age + Biochemical markers (b-hCG, PAPPA)Q70%Maternal age + Radiology (USG- NT>3mm)80%-83%Combined test: Mat. Age + Radiology (USG-NT>3mm)82%-87%*PAPPA is Pregnancy Associated Plasma Protein A