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What is Yolk sac is seen earliest at what stage of gestational age- and explain in detail?
Ans. is 4a' i.e., 5[?]5 weeks o Using transvaginal sonography, yolk sac always visible at 5[?]5 weeks gestational age. (when mean sac diameter- 5 - 8 mm).o Using transabdominal approach, yolk sac should be evident by 7 weeks gestation, when mean sac diameter is 20 mmo Cardiac activity should be detected at 6 - 6-5 weeks gestation by TVS and 8 weeks by using TAS.