ACE2 and infection: Our study did not detect a statistically significant difference in the expression of ACE2 receptors in the placental tissue of patients infected with SARS-CoV-2 during pregnancy and the control group, nor between the subgroups formed according to the severity of the clinical presentation or the trimester in which the infection occurred but confirmed a positive correlation between the level of ACE2 expression in placental tissue and elevated concentration levels of O2-superoxide anion radicals in maternal blood.