Definition - What does Pseudogestational Sac mean?
A pseudogestational sac is a buildup of fluid within the uterus that mimics a gestational sac, giving the false appearance of pregnancy.
With the use of modern ultrasound technology, the differentiation between the two should not be difficult.
A pseudogestational sac is also known as intra-cavity fluid.
FertilitySmarts explains Pseudogestational Sac
A gestational sac is a fluid-filled structure that surrounds a developing embryo in the very early stages of pregnancy. It is the first visual evidence of pregnancy before the embryo is even visible.
A pseudogestational sac is caused by bleeding from the inner uterine lining (endometrium) that has been prepared for pregnancy. This results in a collection of fluid within the uterus that can appear similar to the fluid-filled structure of a gestational sac.
True Gestational Sac
A normal gestational sac is located present close to the periphery or edge of the uterus as it is embedded in the endometrium.
A normal gestational sac along with its contents gives an appearance of two small bubbles on an ultrasound scan, referred to as the “double sac sign.”
With true sacs, the ultrasound will eventually show a yolk sac and an embryo.
A pseudogestational sac is situated in the center of the endometrial cavity.
A pseudogestational sac does not have a “double sac sign.” However, the absence of this sign does not necessarily denote the presence of a pseudosac.
With a pseudosac, the uterus will remain empty and no yolk sac or embryo will show on an ultrasound.
As opposed to a true sac, a pseudosac may be associated with the presence of free fluid or blood in the pelvis suggesting an ectopic pregnancy, that is not viable and a medical emergency.
The hormonal environment in an ectopic pregnancy (nonviable pregnancies that occur outside of the uterus) can create this collection of fluid, with pseudosacs appearing about 10% of ectopic pregnancies.
A pseudosac differs from an empty gestational sac in that the latter does not indicate an ectopic pregnancy. Beta-hCG levels are used to monitor and differentiate between the two.
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Lin E, et al.
Diagnostic Clues to Ectopic Pregnancy.