A 28-year-old woman with a positive pregnancy test undergoes transvaginal ultrasound, which shows a fluid collection within the endometrial cavity. Which feature identifies this collection as a pseudogestational sac rather than an early intrauterine pregnancy?

• A It enlarges proportionally with rising serum beta-hCG
• B It is surrounded by two concentric echogenic rings
• C It is placed eccentrically within the decidua
• D It lies centrally within the endometrial cavity and contains no yolk sac ✓

Explanation

D pseudogestational sac is a small amount of fluid within the decidualised uterine cavity itself, so it sits centrally and lacks a yolk sac, fetal pole, and the double decidual sac sign. D true gestational sac is eccentrically embedded in the decidua with a double decidual reaction, which corresponds to option B. Option C describes a true sac, and pseudosacs do not track beta-hCG growth.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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