A 25-year-old woman at 6 weeks amenorrhoea with beta-hCG of 3000 mIU/mL has an ultrasound showing a fluid collection within the endometrial cavity surrounded by a single echogenic rim, eccentrically placed, with no yolk sac or fetal pole and no peritrophoblastic flow on Doppler. What is the MOST likely nature of this collection?
- A Early intrauterine gestational sac
- B Pseudogestational sac of an ectopic pregnancy ✓
- C Submucous fibroid with cystic degeneration
- D Haematometra from cervical stenosis
Correct answer: B. Pseudogestational sac of an ectopic pregnancy
Explanation
A pseudogestational sac is a blood or fluid collection within the decidua caused by the hormonal milieu of an ectopic pregnancy. It is centrally located within the cavity rather than eccentrically implanted, lacks a double decidual sac sign, contains no yolk sac or embryo, and shows no peritrophoblastic flow. Its presence alongside an adnexal mass or rising beta-hCG supports ectopic pregnancy until proven otherwise.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.