Which imaging modality confirms placenta previa?

• A. Ultrasound.
• B. MRI.
• C. CT scan.
• D. X-ray.

Answer: (A)

Ultrasound is the imaging modality used to confirm placenta previa. It provides real-time visualization of placental location relative to the internal cervical os, which is the defining feature of placenta previa. A transabdominal scan is usually done first to map the placenta; if the placenta is low-lying or image quality is limited, a transvaginal scan offers higher resolution near the cervix and gives a more precise assessment of whether the placenta covers the internal os. This approach is preferred because it is safe for the fetus and widely available. MRI can be considered as an adjunct when ultrasound findings are inconclusive or when detailed placental mapping is needed, but it is not the first-line test. CT and X-ray involve ionizing radiation and are not used to diagnose placenta previa.