| • The villi still have a normally cellular interior with preserved fetal vessels.
• The trophoblast still appears intact.
• However the maternal space is filled with a mixture of blood and fibrin platelet thrombus.
• Circulation has stopped in the maternal space. |
| Placental Infarct |
| Etiology |
•Decidual vascular thrombosis or •Absence or abnormal conversion of decidual vessels or •Fibrinoid necrosis and atherosis of decidual vessels •Can lead to a cessation in blood supply to intervillous space and
subsequent collapse of villous architecture and agglutination of villi |
| Pathogenesis |
•Cessation of blood supply to intervillous space and subsequent collapse
of villous architecture and agglutination of villi with death of villous
trophoblast followed by death of villous stroma and fetal vessels |
| Epidemiology |
•Marginal infarcts (<1cm) present in 10% of normal term
deliveries •More significant number and size of infacts seen in preclampsia, intrauterine growth retardation,
anti-phospholipid antibody syndrome |
| Clinical |
•Small infarcts are usually asymptomatic •Multiple infarcts associated with preeclampsia or severe hypertension may
involve enough of placental parenchyma to lead to fetal demise |
| General Gross Description |
•Acute infarcts (2-3 days old) usually red and firm •Subacute infarct (3-5 days old) usually pink-tan and firm •Old infarcts usually white-tan and firm •Wedge shaped with apex at maternal surface •Can be located marginally or centrally •Can range in size from small to massive |
| General Micro Description |
•Acute infarcts (2-3 days old) show collapse of intervillous space. Villi
appear to agglutinate and have lost their outer trophoblast layer, but fetal
vasculature can still remain or be degenerating with intervillous
hemorrhage. •Old infarcts have virtually no blood in intervillous space and villi have
no nuclei whatsoever with pale pink outlines of their shape. These are the
so calledd "ghost villi". •Subacte infarcts have microscopic features intermediate between acute and old
infarcts |
| Reference |
•Salafia and Popek "Placenta" (Chaper 69) in Damjanov and Linder (eds)
Anderson^s Pathology 10th edition, St Louis: Mosby, 1996, p2317. •Cunningham et al Williams Obstetrics, Norwalk: Appleton and Lange, 1993,
p742-744.
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