In the U.S., group B strep is 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 25% of pregnant women carry group B strep in the rectum or vagina. Group B strep bacteria may come and go in people’s bodies without symptoms.
CDC’s guidelines recommend that a pregnant woman be tested for group B strep when she is 35 to 37 weeks pregnant.
A pregnant woman who tests positive for group B strep and gets antibiotics during labor has only a 1 in 4,000 chance of delivering a baby with group B strep disease, compared to a 1 in 200 chance if she does not get antibiotics during labor.
Any pregnant woman who had a baby with group B strep disease in the past, or who has had a bladder (urinary tract) infection during this pregnancy caused by group B strep should receive antibiotics during labor.