At what size of mean gestational sac diameter measured on TVS with no embryonic pole is labelled as 'Anembryonic Gestation' -: (A) 15mm, (B) 20mm, (C) 25mm, (D) 30mm
Answer is C. An intrauterine gestational sac is reliably visualized with transvaginalsonography by 5 weeks, and an embryo with cardiac activity by 6 weeks The embryo should be visible transvaginally once the mean sac diameter hasreached 25 mm--otherwise the gestation is anembryonic. Cardiac motion isusually visible with transvaginal imaging when the embryo length reaches 5 mm.