Fast Facts

Rates of serious group B strep (GBS) infections are higher among newborns, but anyone can get GBS disease. Below are some important facts about GBS disease in babies, pregnant women, and others.


  • Among babies, there are 2 main types of GBS disease:
    • Early-onset — occurs during the first week of life.
    • Late-onset — occurs from the first week through three months of life.
  • In the United States, GBS bacteria are a leading cause of meningitis and bloodstream infections in a newborn’s first three months of life.
  • Early-onset disease used to be the most common type of GBS disease in babies. Today, because of effective early-onset disease prevention, early- and late-onset disease occur at similarly low rates.
  • In the United States on average each year:
    • About 930 babies get early-onset GBS disease.
    • About 1,050 babies get late-onset GBS disease.
  • Newborns are at increased risk for GBS disease if their mother tests positive for the bacteria during pregnancy.
  • 2 to 3 in every 50 babies (4–6%) who develop GBS disease die.

Pregnant Women

  • About 1 in 4 pregnant women carry GBS bacteria in their body.
  • Doctors should test pregnant woman for GBS bacteria when they are 36 through 37 weeks pregnant.
  • Giving pregnant women antibiotics through the vein (IV) during labor can prevent most early-onset GBS disease in newborns.
    • A pregnant woman who tests positive for GBS bacteria and gets antibiotics during labor has only a 1 in 4,000 chance of delivering a baby who will develop GBS disease. If she does not receive antibiotics during labor, her chance of delivering a baby who will develop GBS disease is 1 in 200.
  • Pregnant women cannot take antibiotics to prevent early-onset GBS disease in newborns before labor. The bacteria can grow back quickly. The antibiotics only help during labor.

Other Ages and Groups

  • GBS bacteria may come and go in people’s bodies without symptoms.
  • On average, about 1 in 20 non-pregnant adults with serious GBS infections die.
  • The rate of serious group B strep disease increases with age:
    • There are 10 cases in every 100,000 non-pregnant adults each year.
    • There are 25 cases in every 100,000 adults 65 years or older each year.
  • The average age of cases in non-pregnant adults is about 60 years old.