Which one of the following is true about visualization of gestational sac?
All the structures are visualized at least 1 week earlier in a transvaginal USG. The positive sign that can be elicited earliest in the pregnancy is visualization of the gestational sac or fetus. With transvaginal ultrasound the gestational sac can be seen as early as 10 days after implantation.
a) Detected at 4 - 5 weeks by transvaginal USG
b) Detected at 5 - 6 weeks by transabdominal USG
c) Detected at 3 - 4 weeks by transabdominal USG
Both 'a' & 'b'