Table 3.

Comparison of clinical and histological features in infectious villitis and villitis of unknown etiology (VUE) (9).

	Infectious villitis	VUE
Prevalence	0.1-0.4%	5-15%
Histological features	Diffuse distribution Histiocytic villitis Presence of villous plasma cells Haemosiderin deposition Viral inclusion bodies	Focal or patchy distribution Lymphohistiocytic villitis Absence of plasma cells Absence of haemosiderin Absence of viral inclusion bodies
Symptomatic maternal infection during pregnancy	Common	Rare
Association with maternal autoimmune disease	Rare	Common
Recurrence	Rare	Common