Effect of SARS-CoV-2 on the human placenta

SARS-CoV-2 infection during pregnancy leads to an increased risk of adverse pregnancy outcomes. To determine the host response of the human placenta to SARS-CoV-2 infection, we performed RNA-Seq on placentas from COVID-19+ and COVID-19- mothers, as well as placentas that presented with non-COVID related inflammatory pathologies. We found that placentas infected by SARS-CoV-2 at term show an induction of inflammatory genes, including a robust increase in chemokine and cytokine signaling. Furthermore, when SARS-CoV-2 is detected in the placenta, placenta cell marker identity genes are lost with a concomitant increase in macrophage gene expression. Furthermore, when infected ex vivo, a strong inflammatory response and cellular de-identification is similarly observed, along with an acute increase in cell death in response to viral infection. Our data describes the inflammatory responses that occur in the placenta after SARS-CoV-2 infection both acutely and long-term, and provides a comparison with other placental inflammatory pathologies. Overall design: Examination of the transcriptomes of placenta samples at time of delivery (n=5 health control, n=17 maternal COVID+, n=4 other inflammatory pathologies) and when infected with SARS-CoV-2 ex vivo (n=3 biological replicates)