Overdistended bladder mimicking placenta previa

Transabdominal study shows an over-distended bladder giving the appearance of placenta previa in a patient without a previa. The over-distended bladder has compressed the anterior lower uterine segment against the posterior lower uterine segment, thereby mimicking placenta previa. The arrow points to where the internal os was thought to be before the bladder was emptied. When the cervix and placenta were reassessed after the patient emptied her bladder, the area between the placental edge and internal os could be visualized.