<prompt> Gestational sac is seen by TVS at-5 weeks6 weeks7 weeks8 weeks  <response>: Ans. is a i.e., 5 weeks Ref: Duttas Obs 7thep. 68TVS showso Gestational sac yolk sac - 5th weeko Fetal pole cardiac activity - 6th weeko Embryonic movements - 7th weeko Fetal gestational age is best determined by CRL between 7th to 12th weeks variation - 5 dayso Doppler effect of ultrasound can pick up heart rate by 10lh week. 