Pseudogestational Sac

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.

Pseudogestational sac

• 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.

Ectopic Pregnancy

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.