Extensive spontaneous retroperitoneal hemorrhage: an unusual complication of heparin anticoagulation during pregnancy.

A 27-year-old patient at 13 weeks' gestation maintained on subcutaneous heparinization due to hemoglobin S and hemoglobin C (SC) sickle cell disease and previous splenic vein thrombosis presented with spontaneous acute onset of severe left lower abdominal and groin pain. The pain, which radiated to the anterior aspect of the thigh, was associated with nausea and vomiting and was exacerbated by extension of the left lower extremity. The patient was hemodynamically stable, yet during the first 24 h of hospitalization a marked decrease in hematocrit from 29% to 22% occurred. Contrast computed tomography (CT) revealed an extensive abdominal-pelvic, retroperitoneal hematoma extending approximately 15 cm in length from above L5 cephalad to below the greater trochanter of the left femur caudally. The retroperitoneal hemorrhage self-tamponaded and did not require surgical management. The dosage of heparin was decreased and maintained with appropriate activated partial prothrombin (aPTT) levels. To our knowledge, this is the first report of a spontaneous retroperitoneal hemorrhage complicating heparin anticoagulation in pregnancy. Unusual hemorrhagic complications of anticoagulation therapy are discussed.