Application of the Amsterdam Placental Workshop Group Consensus Statement in the Systematized Evaluation of Early Pregnancy Loss: Increased Diagnostic Yield and Clinical Utility.

Abstract

The Amsterdam Placental Workshop Group Consensus Statement has been validated for term placentas, but its use in the evaluation of early pregnancy loss remains insufficiently studied and underutilized in clinical practice. To assess the diagnostic utility of applying the Amsterdam consensus to histopathologic evaluation of early pregnancy loss. We conducted a retrospective study of 269 early pregnancy loss events at a tertiary hospital. Each case underwent routine evaluation and blinded reanalysis by 2 pathologists using the Amsterdam consensus definitions. Intervillous fibrin deposition, not part of the original criteria, was also systematically graded. Clinical variables were collected to explore associations with histologic findings. Routine evaluation identified potentially relevant findings in 3 of 269 cases (1.1%). Structured reanalysis increased this number to 13 of 269 (4.8%; P < .001), mainly due to maternal vascular malperfusion. When intervillous fibrin deposition was included, abnormal cases rose to 47 of 269 (17.5%; P < .001). Maternal vascular malperfusion was observed in 13 of 269 cases (4.8%) and fibrin deposition in 34 of 269 (12.6%); none were detected in routine evaluation. In addition, the 3 cases reported as pathologic in the routine evaluation were reclassified in the reevaluation, and 2 of these as normal. Pathologic findings correlated with higher gestational age and multiple pregnancies. Applying the Amsterdam criteria, with the additional evaluation of intervillous fibrin deposition, improves diagnostic yield and consistency in early pregnancy loss, uncovering lesions missed in routine clinical practice.