Subchorionic hemorrhage: sonographic diagnosis and clinical significance.

Twenty-one pregnancies with sonographic evidence of subchorionic hemorrhage were evaluated clinically and sonographically. Clinical evaluation included maternal age, gravidity, parity, gestational age, presence of pain, presence and amount of bleeding, and pregnancy outcome. Sonographic evaluation included the relative and absolute size of the hematoma, its echogenicity and location in relation to the placenta, the presence of marginal placental abruption, and progress on follow-up examinations. The outcome of these pregnancies was unfavorable in 15 cases (71%) and correlated well with the relative and absolute size of the hematoma, severity of vaginal bleeding, change in hematoma size on follow-up examination, and presence of pain. There was no significant correlation between the outcome and the echogenicity of the hematoma, presence of placental margin elevation, gestational and maternal age, gravidity, or parity. All hematomas extended to the margin of the placenta. Subchorionic hemorrhage is a frequent cause of first and second trimester bleeding and has a grave prognosis. Familiarity with the varied sonographic appearances and meticulous sonographic examination with special attention to the placental margins can be helpful in the diagnosis.