Rubella infection (RuV) during early pregnancy is a known cause of congenital rubella syndrome (CRS). However, the mechanisms by which the virus crosses the placenta and infects the fetus are not fully understood. It has been known that various kinds of cell stresses can occur during the placenta formation. Previously, we demonstrated that low-glucose-induced endoplasmic reticulum stress could drastically enhance RuV infection in immortalized human first-trimester trophoblast cells. In this study, we investigated the roles of oxidative stress in RuV infection in these cells. Oxidative stress was induced in Swan.71 cells by culturing them in medium containing hydrogen peroxide (H