Introduction. Accurate placenta pathology assessment is essential for clinical management of mother and newborn health1,2,3. Placental pathology informs immediate clinical treatment, predicts recurrence risk in subsequent pregnancies and long-term maternal and child adverse outcomes, and explains underlying causes of pregnancy loss3,4. Ongoing placental pathology research can determine new biomarkers of disease, such as the recently identified SARS-CoV-2 placentitis5,6, and improve our und...