In threatened abortion, which ultrasound finding MOST strongly predicts inevitable progression to complete abortion?

• A Fetal heart rate of 110 bpm at 7 weeks
• B Crown-rump length 2 mm below the mean for gestational age
• C Subchorionic haematoma ≥ 25% of gestational sac volume ✓
• D Yolk sac diameter of 4 mm at 7 weeks

Explanation

A subchorionic haematoma (SCH) that occupies ≥ 25% of the gestational sac volume is associated with a significantly increased risk of complete pregnancy loss, regardless of the presence of cardiac activity. Fetal bradycardia (< 100 bpm, not 110 bpm) is a poor prognostic sign. Minimal CRL discrepancy and a yolk sac up to 5–6 mm at 7 weeks are within normal variation. Large SCH volume is the strongest ultrasound predictor of subsequent loss in threatened abortion.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.