Retroplacental hemorrhage

Retroplacental hemorrhage occurs when there is perigestational hemorrhage that is confined to the retroplacental space.

Pathology

This type of hemorrhage occurs behind the placenta. The hematoma, therefore, separates the placenta from the uterine wall. The source of bleeding is probably from spiral arteries.

Etiology

• in late pregnancy, it is typically caused by a placental abruption

Radiographic features

Ultrasound

Sonographically, a retroplacental hematoma may mimic a thickened placenta because the hematoma is commonly isoechoic to the placenta. It should be suspected if the retroplacental hypoechoic zone is thickened to >2 cm ⁶. Otherwise, the retroplacental hematoma may be hypoechoic or may be of heterogeneous echogenicity.

Color Doppler interrogation will reveal the absence of internal blood flow, this finding allows differentiation of hematomas from other placental masses.

Differential diagnosis​

• focal retroplacental myometrial contraction: transient
• causes of placentomegaly: particularly in isoechoic hematoma
• retroplacental uterine leiomyoma: consider in hypoechoic hematoma