Reproducibility of the Amsterdam consensus criteria for maternal vascular malperfusion (MVM): a multicenter evaluation of perinatal pathologists

Objectives: Maternal vascular malperfusion (MVM) refers to dysfunctional uteroplacental circulation and is associated with increased risk of adverse maternal and fetal outcomes. The diagnosis of MVM is one of the most common pathological diagnoses in term placentas. The aim of the study was to test the interrater reliability of the MVM Amsterdam criteria. Methods: A group of 12 international perinatal pathologists reviewed digital histological sections of placentas (n=29; 20 MVM/ 9 non-MVM controls), applying published Amsterdam workshop consensus criteria. Kappa statistics were used for interobserver agreement analysis. Results: Agreement levels on final MVM diagnosis according to Amsterdam consensus were calculated as slight to fair (K-values of 0.187 and 0.260, p<0.001). Substantial agreement was reached one time for infarcts (K-value of 0.707, p<0.001). Complementary tested criteria achieved none to moderate agreement. Conclusions: Our results highlight the need to refine current MVM criteria to support consistent international diagnosis.