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UW Health SMPH
American Family Children's Hospital
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Screening for Group B Strep

Group B streptococcus (GBS) is a type of bacteria normally found in the bowel of up to 35 percent of healthy adults. In women, GBS can also be found in the vagina and bladder. Although similar in name, GBS is different from Group A Strep, the bacteria that causes “strep throat.”

 
A person whose body carries GBS but shows no sign of infection is said to be “colonized.” In certain circumstances, GBS can invade the body and cause a serious infection. Many of these infections occur in the elderly or in those with chronic medical conditions.
 
If a pregnant woman is colonized by GBS, she can pass it to her baby during childbirth. Most babies who get GBS from their mothers do not have any problems, but about 8,000 babies per year born in the United States develop serious GBS disease. This includes sepsis (blood infections), meningitis (infection of the fluid and lining surrounding the brain) and pneumonia. Up to 15 percent of these babies die, and those that survive may have long-term problems such as hearing and vision problems.
 
We recommend that you be screened for GBS during your pregnancy. A vaginal culture is performed at approximately the 36th week of pregnancy. If the culture is positive, showing that GBS is present, we will recommend antibiotics during labor to help prevent GBS from being passed to your baby.
 
Remember, although GBS is fairly common in pregnant women, very few babies actually get sick from a GBS infection. If you have any questions about GBS, please do not hesitate to ask at your next prenatal visit.