Does Amsterdam criteria applied to largely unsubmitted term placentas with favorable fetal outcomes show significant maternal clinicopathologic correlation?

Objectives: Before the Amsterdam Placental Workshop Group Consensus Statement, standardization in placental pathology assessment did not exist. This study evaluated the Amsterdam criteria's utility in correlating ischemic placental disease (IPD) with placental pathologic lesions in a cohort of largely unsubmitted term placentas with favorable outcomes.

Methods: In this prospective case-controlled study at a single institution, all placentas were examined using Amsterdam protocols for gross sampling and microscopic review by 2 reviewers who were blinded to clinical history. Pathologic findings including hypoxic and chronic villitis of unknown etiology (VUE) scores were correlated with IPD status and whether the placenta was submitted to pathology using either a χ² test or Fisher exact test, as appropriate.

Results: A total of 172 placentas collected between 2017 and 2020 were included. Approximately 18.6% (n = 32) were in the IPD group, and 81.4% (n = 140) were in the non-IPD group. No statistically significant differences in microscopic findings were seen in ascending infection, maternal vascular malperfusion, fetal vascular malperfusion, or VUE between groups or by submission status. When tabulated as a hypoxic score, placentas from the IPD group were associated with greater hypoxic scores compared to non-IPD placentas (P = .011). A positive association was observed between greater VUE scores and hypoxic scores (P = .007).

Conclusions: In largely unsubmitted term placentas, the microscopic findings per Amsterdam criteria may be nonspecific. When tabulated as hypoxic or VUE scores, however, some clinicopathologic correlation may be seen in the setting of IPD. Further work is needed to refine the thresholds of meaningful reporting of placental pathology using the Amsterdam criteria.