Group B streptococcus (GBS) is a type of bacteria that can cause infection in pregnant women and their newborns. About 1 in 4 pregnant women carry GBS bacteria in their body. GBS most often is found in the vagina and rectum, and it can pass from the mother to the fetus during labor. While GBS usually does not cause harm to the mother, it can cause serious infections in the baby, including infections of the blood, spinal fluid, and lungs.
To prevent GBS disease in newborns, doctors and midwives should test pregnant women for GBS bacteria when they are 36 through 37 weeks pregnant. If a woman tests positive for GBS, she can receive antibiotics through the vein (IV) during labor to prevent most cases of GBS disease in newborns during the first week of life. Women who have had a previous baby that had a GBS infection or women who during the current pregnancy have a urinary tract infection with GBS have an increased risk of having a baby with GBS infection and can benefit from receiving antibiotics during labor.
It is important to note that if a test finds GBS, it means only that the woman has the bacteria in her body, not that she or her baby will become sick from it. Most healthy babies born to GBS-positive mothers are simply watched to see if they have signs of infection. However, babies who get GBS disease are treated with antibiotics.
