A case of spontaneous rectus sheath hematoma is reported in a 32-year-old multigravida transferred to our antepartum unit for premature labor and persistent cough related to Candida dubliniensis upper airway infection. In pregnant patients presenting sudden-onset severe abdominal pain and parietal tenderness, there are two main differential diagnoses: abruptio placentae and aseptic necrobiosis of a uterine leiomyoma. The correct diagnosis may be obtained by ultrasonography and sometimes by computed tomography. In the present case an emergency cesarean section was performed at 35 weeks gestation after a 40% decrease in maternal hemoglobin and onset of fetal heart rate anomalies.