Twin Pregnancy with Complete Hydatidiform Mole and Co-existent Live Fetus

A 14-week pregnant woman had a mixed echogenic mass of size 4x12 cm at placenta portion and normal fetus at ultrasound. The image of the mass was very similar to a huge subchorionic hematoma (SCH). The fetal chromosomes by amniocentesis were normal. The presumed diagnoses were huge SCH or twin pregnancy with complete hydatidiform mole and co-existent fetus (CHMCF). A male fetus weighing 760 g was delivered at 25 gestational weeks. The findings on the placental biopsy showed twin pregnancy with CHCMF. With ultrasound findings of this type, the possibility of a huge SCH and twin pregnancy with CHMCF should be considered.