ACE2 and COVID-19: However, a secondary effect of SARS-CoV-2 on feto–maternal circulation and placentation caused by substantial ACE2 depletion has received little attention.6,43,48 Based on the above theory, we hypothesize that, during pregnancy, the ACE2 receptor serves as the binding site for SARS-CoV-2, thereby augmenting the severity of COVID-19 and the incidence of unfavorable outcomes, such as premature birth and preeclampsia (Figure 2).