Streptococcus B infection can occur even in newborns born by cesarean section, but it is less likely than in babies born vaginally, but it does not mean that they are absolutely immune to infection. Especially if the baby is delivered by cesarean section after vaginal trial of labor, or if the baby is delivered by cesarean section after premature rupture of membranes, the chance of the newborn being infected with group B streptococcus during cesarean section is still very high. It is a critical emergency in neonatology. Therefore, pregnant women should be checked for group B streptococcal infection in late pregnancy, and if there is a need for early treatment.