Earliest diagnosis of pregnancy can be established safely by:

Ans: A. USG for fetal cardiac activity (Ref Williams 24/e p196; Ultrasound Obstet Gynecol 2011; 37:625-628; Dutta 8/e p77-78, 7/e p68)Earliest diagnosis of pregnancy:Most accurate & safest method diagnose ble pregnancy at 6 weeks = USG for fetal cardiac activity.Transvaginal sonography:By 5 weeks:Reliably visualizes intrauterine gestational sac.Embryo visible transvaginally once mean sac diameter is 20 mm.Otherwise is anembryonic gestation.By 6 weeks:Embryo with cardiac activity.Cardiac motion visible when embryo length is 5 mm.If embryo <7 mm is unidentified with cardiac activity - Subsequent examination recommended in 1 week (American Institute of Ultrasound in Medicine, 2013a).Doppler:Most sensitive but unsafe in early pregnancy.Doppler examination of fetal vessels in early pregnancy should not be performed without a clinical indication.