• Cross section of placenta; fetal surface at top.

• Long arrow = retroplacental hemorrhage.

• Short arrows = area of infarcted villi due to compression.

• Trauma including accidents and amniocentesis

• Decidual vascular pathology associated with preeclampsia or anticardiolipin antibodies

• Abnormal uterine shape

• Placenta praevia

• Cocaine

• Separation of the placenta by retroplacental hemorrhage from the uterus prior to delivery of the fetus.

• Hemorrhage may extend into the intervillous space

• Compression with hemorrhage in the villus stroma and/or infarct may occur

• Secondary to vascular rupture (fibrinoid necrosis), sudden vascular hypertension with bleeding (cocaine•) or vascular thrombosis

• <1% of pregnancies based on clinician^s estimate

• 2-4% of placentas examined microscopically show some evidence of abruption

• Present with abdominal pain and vaginal bleeding

• Extent of vaginal bleeding may depend on location of rupture (marginal or central)

• Hemorrhage may be substantial and result in fetal mortality.

• Retroplacental blood clot which may be very adherent to maternal surface

• May be compression and infarct of adjacent villi.

• Clot may vary from acute to old although it will not organize

• Villi may show hemorrhage into the stroma

• Villous infarcts may be seen.

• Benirschke K, Kaufmann P. Pathology of the human placenta, 3rd ed. New York: Springer-Verlag, 1995, pp. 496-508.

• Current literature from PubMed at National Library of Medicine