**6. Chronic intervillositis**

Chronic intervillositis, also known as massive chronic intervillositis or chronic histiocytic intervillositis, is an exceptionally rare placental anomaly, defined by inflammatory placental lesions [1], mainly diffuse histiocytic infiltrate in intervillous space [41]. Among risk factors, maternal diabetes, maternal hypertension, intravenous drug abuse, preeclampsia, and systemic lupus erythematosus are mentioned. This condition has a perinatal mortality of 80%, due to an associated risk of recurrent spontaneous abortion [42], fetal growth restriction [43], and fetal death. The recurrence rate is considered to be above 60%.
