Pathological examination of the placenta is not universally performed and has not received as much general interest as many other areas of surgical pathology. This is in response to many factors, one of which is the misconception that the relevance of pathologic diagnoses in the placenta is of lesser importance than that of other subspecialties.
Of the myriad of placental pathologic findings with clinical implications, those with recurrence risks are especially important for families and for providers. There are just a handful of such lesions, and they remain biologic curiosities without specific known aetiologies. These lesions, villitis of unknown aetiology, chronic histiocytic intervillositis/ massive chronic intervillositis, and massive perivillous fibrin deposition/maternal floor infarct, have in addition to their predisposition to recur in subsequent pregnancies, significant associated increase in perinatal morbidity and mortality. We have encountered many sad cases of multiple perinatal losses due to one of these pathologies, and the personal grief and clinical frustration should not be underestimated. Examination of the placenta in these cases may not only assist in the current delivery but also in planning of future pregnancies.
The placenta can uniquely show whether injuries were primarily related to labour/ delivery or to an in-utero insult long before the onset of labour. Determining the timing of such injuries was invaluable in the medicolegal assessment of cases. A meaningful interaction among obstetric staff, mothers and pathologists often obviates need for legal intervention in an unexpected pregnancy outcome.