Maternal-Fetal Immune Responses in Pregnant Women Infected with SARS-CoV-2

Garcia-Flores, Valeria; Romero, Roberto; Xu, Yi; Theis, Kevin; Arenas-Hernandez, Marcia; Miller, Derek; Peyvandipour, Azam; Galaz, Jose; Levenson, Dustyn; Bhatti, Gaurav; Gershater, Meyer; Pusod, Errile; Kracht, David; Florova, Violetta; Leng, Yaozhu; Tao, Li; Faucett, Megan; Para, Robert; Hsu, Chaur-Dong; Zhang, Gary; Tarca, Adi L.; Pique-Regi, Roger; Gomez-Lopez, Nardhy

Pregnant women are a high-risk population for severe/critical COVID-19 and mortality. However, the maternal-fetal immune responses initiated by SARS-CoV-2 infection, and whether this virus is detectable in the placenta, are still under investigation. Herein, we report that SARS-CoV-2 infection during pregnancy primarily induced specific maternal inflammatory responses in the circulation and at the maternal-fetal interface, the latter being governed by T cells and macrophages. SARS-CoV-2 infection during pregnancy was also associated with a cytokine response in the fetal circulation (i.e. umbilical cord blood) without compromising the cellular immune repertoire. Moreover, SARS-CoV-2 infection neither altered fetal cellular immune responses in the placenta nor induced elevated cord blood levels of IgM. Importantly, SARS-CoV-2 was not detected in the placental tissues, nor was the sterility of the placenta compromised by maternal viral infection. This study provides insight into the maternal-fetal immune responses triggered by SARS-CoV-2 and further emphasizes the rarity of placental infection.