The most common etiologies are RPOC, subinvolution of the placental bed, or infection. RPOC are more likely after vaginal delivery, whereas postpartum endometritis is more common after cesarean. Less common causes include, but are not limited to, coagulopathy, pseudoaneurysm or AVMs, dehiscent cesarean scar, or GTD. Primary PPH is considered a risk factor for secondary PPH. CT Abdomen and Pelvis In the setting of hemorrhage, the primary role of CT is to determine whether active ongoing hemorrhage is present, to localize the bleeding, and to identify the source, which is best accomplished with a CT with IV contrast. There is little clinical utility in a noncontrast CT or CT with and without IV contrast in the setting of active ongoing hemorrhage. In hemodynamically stable patients with delayed PPH, multiphasic CTA can be useful in localizing the source of extravasation for targeted therapy [12,29], particularly in suspected intra-abdominal hemorrhage [12]. CT can detect vascular complications such as supraumbilical and perivaginal space hematoma and delineate the relationship to adjacent organs (supralevator versus infralevator location in the perivaginal space) [12,14,15]. Although the diagnosis of complete uterine inversion is made clinically, subacute partial uterine inversions may be detected as a concavity of the uterine fundus in CT [12]. RPOC can be difficult to differentiate from blood products even on multiphase CT [12]. Endometritis is a clinical diagnosis with a nonspecific CT appearance of a thickened heterogeneous endometrium with fluid, gas, and debris within the cavity [15]. Superimposed parametrial abscess or infected hematoma and other complications such as ovarian vein thrombosis [14,15] can be detected on CT.
Postpartum Hemorrhage. The most common etiologies are RPOC, subinvolution of the placental bed, or infection. RPOC are more likely after vaginal delivery, whereas postpartum endometritis is more common after cesarean. Less common causes include, but are not limited to, coagulopathy, pseudoaneurysm or AVMs, dehiscent cesarean scar, or GTD. Primary PPH is considered a risk factor for secondary PPH. CT Abdomen and Pelvis In the setting of hemorrhage, the primary role of CT is to determine whether active ongoing hemorrhage is present, to localize the bleeding, and to identify the source, which is best accomplished with a CT with IV contrast. There is little clinical utility in a noncontrast CT or CT with and without IV contrast in the setting of active ongoing hemorrhage. In hemodynamically stable patients with delayed PPH, multiphasic CTA can be useful in localizing the source of extravasation for targeted therapy [12,29], particularly in suspected intra-abdominal hemorrhage [12]. CT can detect vascular complications such as supraumbilical and perivaginal space hematoma and delineate the relationship to adjacent organs (supralevator versus infralevator location in the perivaginal space) [12,14,15]. Although the diagnosis of complete uterine inversion is made clinically, subacute partial uterine inversions may be detected as a concavity of the uterine fundus in CT [12]. RPOC can be difficult to differentiate from blood products even on multiphase CT [12]. Endometritis is a clinical diagnosis with a nonspecific CT appearance of a thickened heterogeneous endometrium with fluid, gas, and debris within the cavity [15]. Superimposed parametrial abscess or infected hematoma and other complications such as ovarian vein thrombosis [14,15] can be detected on CT.