OBJECTIVE: The objectives of the study are to describe the obstetric outcomes associated with massive perivillous fibrin deposition (MFD) compared with a control series and to determine if outcome differs according to the extent of fibrin deposition. METHODS: Retrospective case-control study based on placentas analyzed over a consecutive 12-year period. MFD was considered severe if it extended over more than 50% of the placenta and moderate between 25% and 50%. RESULTS: During the study period, MFD was observed on 71 placentas, 39 severe and 32 moderate. Compared with the 142 control women, the 39 women with severe MFD more often had histories of autoimmune disease and intrauterine fetal death. The case women with MFD were associated with elevated levels of maternal alpha-fetoprotein and with a high risk of severe growth restriction and/or intrauterine death. Compared with the infants with moderate MFD, those with severe MFD had also more abnormal umbilical artery Doppler velocimetry findings and more often intrauterine deaths and lower birthweights. CONCLUSIONS: Regardless of their extent, MFD that covered at least 25% of the placenta was almost always accompanied by severe growth restriction and by a high risk of intrauterine fetal death. Moreover, severe MFD tend to be associated with autoimmune diseases of the mothers, and pregnancies show more often a pathologic Doppler of the umbilical arteries and more often intrauterine fetal death that the moderate form. © 2017 John Wiley & Sons, Ltd.