A woman at 36 weeks with a suspected placenta previa major undergoes colour Doppler ultrasound. Turbulent subplacental lacunar flow with multiple venous lakes and loss of the hypoechoic retroplacental zone on B-mode are noted. These findings are most consistent with:

• A Placenta praevia without accreta
• B Placenta accreta spectrum (PAS) — morbidly adherent placenta ✓
• C Circumvallate placenta
• D Velamentous cord insertion

Explanation

Ultrasound features of placenta accreta spectrum (PAS) include: loss of the normal hypoechoic (clear) retroplacental zone, presence of multiple intraplacental lacunae ('moth-eaten' or 'Swiss cheese' appearance), turbulent lacunar blood flow on Doppler, and bladder wall irregularity or interruption in percreta. Placenta praevia without PAS maintains the retroplacental hypoechoic zone. Circumvallate placenta and velamentous cord insertion are separate structural anomalies without these Doppler features.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.