In the United States, group B strep (GBS) bacteria are the leading cause of meningitis (infection of the fluid and lining around the brain) and sepsis (infection of the blood) in a newborn’s first week of life (early-onset disease).
About 1 out of every 4 pregnant women carry group B strep bacteria in the rectum or vagina. Group B strep bacteria may come and go in people’s bodies without symptoms.
Pregnant woman should be tested for group B strep bacteria when they are 35 to 37 weeks pregnant.
A pregnant woman who tests positive for group B strep bacteria and gets antibiotics during labor has only a 1 in 4,000 chance of delivering a baby who will develop group B strep disease, compared to a 1 in 200 chance if she does not.
Any pregnant woman who had a baby with group B strep disease in the past, or who has had group B strep in their urine during this pregnancy caused by group B strep should get antibiotics during labor.
Most early-onset group B strep disease in newborns can be prevented by giving pregnant women antibiotics (medicine that kills bacteria in the body) through the vein (IV) during labor.
Newborns are at increased risk for a group B strep disease if their mother tests positive for group B strep bacteria during pregnancy.
The antibiotics used to prevent early-onset group B strep disease in newborns only help during labor — they can’t be taken before labor, because the bacteria can grow back quickly.
The rate of serious group B strep disease increases with age; average age of cases in non-pregnant adults is about 60 years old.