Transvaginal ultrasound in a woman with first-trimester bleeding shows a mean gestational sac diameter of 28 mm with no visible embryo. Fetal cardiac activity is absent. What is the correct interpretation?
- A Failed pregnancy (missed abortion) ✓
- B Pregnancy of unknown location
- C Normal early pregnancy, rescan in 1 week
- D Suspected ectopic pregnancy
Correct answer: A. Failed pregnancy (missed abortion)
Explanation
Strict sonographic diagnostic criteria define a failed pregnancy when the mean gestational sac diameter is 25 mm or more without an embryo, or when the crown-rump length is 7 mm or more without cardiac activity. At 28 mm with no embryo the criterion is met and a diagnosis of missed abortion can be made definitively. C sac below these thresholds is classified as a pregnancy of indeterminate outcome and mandates a repeat scan in 7 to 14 days rather than immediate intervention.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.