<prompt> At what level of b-HcG is it that normal pregnancy can be earliest detected by TVS Transvaginal USG :500 IUml1000 IUml1500 IUml2000 IUml  <response>: Critical titre of HcG : For visibility of Gestational sac TVS -1000-1200 IUml TAS -6000 IUml Ref: Datta Obs 9e pg 601. 