On routine second-trimester ultrasound, a woman with a previous lower segment cesarean section has an anterior low-lying placenta. Which sonographic finding most strongly suggests placenta accreta spectrum?
- A Echogenic chorionic plate
- B Multiple irregular vascular lacunae within the placenta with loss of the retroplacental hypoechoic zone ✓
- C Single deep venous channel at the placental margin
- D Thickened placenta measuring more than 4 cm
Correct answer: B. Multiple irregular vascular lacunae within the placenta with loss of the retroplacental hypoechoic zone
Explanation
Irregular placental lacunae (swiss cheese appearance) combined with loss or thinning of the normal hypoechoic retroplacental clear zone are the classic grayscale markers of abnormal trophoblastic invasion, with high predictive value when both are present. Color Doppler adds turbulent high-velocity flow through the lacunae. Placental thickness alone is nonspecific, and an echogenic chorionic plate is a normal finding.
Reference: Ian Donald's Practical Obstetric Problems, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.