Group B streptococcus (GBS) is a type of bacteria that can be found in the vagina and rectum of pregnant women. It is also present in the vagina and rectum of 25% of healthy women. Although it is harmless to the carrier, if left untreated, it can be passed to the baby during childbirth.

GBS is rare in pregnant women, but it can have serious consequences for the fetus, so GBS testing has become a routine test for all pregnant women.

Transmission of group B streptococcus from mother to child occurs mainly during labor or when the membranes rupture prematurely. Currently, with the application of prophylactic antibiotic treatment regimens based on screening results of vaginal swabs in pregnant women at 35-37 weeks of gestation, the rate of newborn infections and deaths due to this disease has significantly decreased.