A 35-year-old woman came with per vaginum bleeding after 10 weeks of amenorrhea. The urine pregnancy test was positive.
On trans-abdominal ultrasonography, two endometrial cavities are seen at the uterine fundus. There is no deep fundal indentation. The left endometrial cavity shows a gestational sac with the a fetal pole and cardiac activity, with an approximate gestational age of 10 weeks and six days. A well-defined hypoechoic collection is located inferior to this gestational sac, approximately 33 cc in volume. The right endometrial cavity shows a gestational-sac like structure without a yolk sac or fetal pole. The mean sac diameter is 26.8 mm corresponding with a gestational age of seven weeks and five days.