Vaginal bleeding in the first trimester of pregnancy is a common complication, with an incidence of 16 to 25%. Subchorionic hemorrhage and subchorionic hematoma are the most common cause of vaginal bleeding in patients who are 10 to 20 weeks gestational age and make up about 11% of cases. Subchorionic hemorrhage is bleeding beneath the chorion membranes that enclose the embryo in the uterus. It appears to occur due to partial detachment of the chorion membranes from the wall of the uterus.  Subchorionic hematoma is another commonly used term for subchorionic hemorrhage. Most women present with light vaginal bleeding, but some are asymptomatic with incidental ultrasound findings.