Table 1.

Definition categories of placental infection with SARS-CoV-2

Definite: evidence of active replicating virus with location in the placental tissues

Probable: evidence of viral RNA or protein located in placental tissues

Possible: evidence of viral RNA in placental homogenates or viral-like particles by electron microscopy in placental tissues

Unlikely: no evidence of any of the above

No testing: testing not done

Roberts et al. Consensus definition of SARS-CoV-2 placental infection. Am J Obstet Gynecol 2021.