A woman with suspected low-lying placenta on a transabdominal scan at 28 weeks requires further imaging to confirm the relationship of the placenta to the internal os. Which approach provides the most accurate assessment?

• A Color Doppler of the uterine arteries
• B Repeat transabdominal sonography with a full bladder
• C Transvaginal sonography ✓
• D Magnetic resonance imaging in all cases

Explanation

Transvaginal sonography is the gold standard for localizing the placenta relative to the internal os because the probe sits close to the cervix without crossing it, and it is safe even in active bleeding. C full bladder on transabdominal scanning can artificially appear to overlie the os, creating a false impression of previa. MRI is reserved for suspected accreta spectrum or equivocal cases, not routine localization.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.