Pregnancy Loss Associated with COVID-19 Infection: Associations with Detection of Viral RNA in Placental and Fetal Tissue.

Background: The purpose of this study was to investigate placental pathology and cause of death (COD) in pregnancy losses associated with maternal COVID-19 infection and examine associations with detection of SARS-CoV-2 in placenta and fetal organs.

Methods: Demographics, placental pathology, and COD information was collected from fetal autopsies done at Evanston hospital, IL between 03/1/2020 and 12/31/2022 where maternal history indicated positive SARS-CoV-2 test during pregnancy or SARS-CoV-2 infection was suspected after fetal autopsy. Polymerase chain reaction (PCR) testing for SARS-CoV-2 RNA was performed on placenta, fetal liver, and lung tissue.

Results: We identified 13 autopsies and detected SARS-CoV-2 in placentas of 5 cases, all showed chronic histiocytic intervillositis (CHI) and massive perivillous fibrin deposition (MPVFD). CHI and MPVFD were absent in all the PCR-negative cases (P < .001). Fetal liver was positive for SARS-CoV-2 in 1 case, which was in the group with negative placental SARS-CoV-2 PCR. The lung tissue was negative in all cases.

Conclusion: We confirm the association between detectable placental SARS-CoV-2 with CHI and MPVFD in placentas from pregnancy losses in mother who had COVID-19 during their pregnancy. Detection of SARS-CoV-2 in fetal liver, despite negative placental tissue, was unexpected and may be important for understanding the impact of maternal COVID infection on neonates.