Sonographic findings and clinical outcomes in women with massive subchorionic hematoma detected in the second trimester.

BACKGROUND: Small hematomas on the placental surface, termed subamniotic hemorrhage, are a common finding either at the routine 18- to 20-week anatomy ultrasound or at subsequent assessments of fetal growth and well-being. Hemorrhage beneath or at the edge of the placenta, or behind an isolated area of the fetal membranes, is of greater concern.

THE CASES: We describe the ultrasound findings and clinical outcomes in two women with a diagnosis of massive intrauterine hematoma arising from the fetal membranes. Both required blood transfusion because of the extent of concealed and revealed bleeding. In each case the initial placental appearances and uterine artery Doppler studies were normal. Both hematomas resolved with growth of the fetus and amniotic sac. Each neonate survived the perinatal period favourably. One was born vaginally at 32 weeks' gestation following premature preterm rupture of the membranes, and the second was born by emergency Caesarean section at 37 weeks because of a recurrence of antepartum hemorrhage.

CONCLUSION: Large intrauterine hematomas may be acutely detrimental to maternal health in the second trimester. Ultrasound assessment of the placenta is useful to define the perinatal prognosis and may demonstrate gradual resolution. Despite a dramatic initial presentation, this finding may be compatible with a favourable outcome.