gestational sac but no yolk sac and embryo is caused by blighted ovum or anembryonic gestation.
gestational sac but no yolk sac and embryo is caused by blighted ovum or anembryonic gestation.
gestational sac but no yolk sac and embryo?
blighted ovum or anembryonic gestation
a blighted ovum or anembryonic gestation is characterized by a normal-appearing gestational sac, but the absence of an embryo. it likely occurs as a result of early embryonic death with continued development of the trophoblast. when small, the sac cannot be distinguished from the early normal pregnancy, as there may be a yolk sac, though a fetal pole is not seen. for diagnosis, the sac must be of sufficient size that the absence of normal embryonic elements is established. the criteria depends on the type of ultrasound exam performed. a pregnancy is anembryonic if a transvaginal ultrasound reveals a sac with a mean gestational sac diameter (mgd) greater than 25 mm and no yolk sac, or an mgd 25 mm with no embryo. transabdominal imaging without transvaginal scanning may be sufficient for diagnosing early pregnancy failure when
blighted ovum
the yolk sac and embryo should be readily identifiable when the gestational sac reaches a certain size — a yolk sac should be seen when the gestational sac is 20mm and a fetal pole should be seen when the gestational sac reaches 25mm.









































gestational sacs can be identified via ultrasound and are generally identified by the following 4 characteristics: 









































bullet::::1. the sac has a round or elliptical shape in longitudinal and transverse views









































bullet::::2. it is surrounded by a white echogenic rim ("choriodecidual reaction")









































bullet::::3. the sac is located in the uterine fundus
gestational sac