Group B Streptococcus

Group B Strep Image
Photo courtesy of CDC / Bette Jensen

Group B streptococcus (GBS) is a bacteria that lives within the vagina and rectum of up to 40% of all normal healthy women. While it rarely causes infection in adults, during delivery it may be passed on to the baby, leading to severe infections such as pneumonia, meningitis, sepsis and even death.

The Centers for Disease Control and Prevention (CDC) has recommended routine screening for GBS for all pregnant women. This screening is performed between the 35th and 37th week of pregnancy by swabbing inside the vagina and around the rectum. If you test positive for GBS this simply means that you are a carrier. Not every baby who is born to a mother who tests positive for GBS will become ill. Approximately one of every 100 to 200 babies whose mothers carry GBS will develop signs and symptoms of GBS disease. Nevertheless, it is recommended that all women who test positive for GBS receive IV antibiotic prophylaxis during labor to prevent transmission to the baby.

If you miss screening during your pregnancy, or the results are not available, we will treat you based on your risk factors for having GBS. The CDC guidelines state these risk factors are

  • Previous infant affected by a GBS infection
  • Gestational age less than 37 weeks
  • Ruptured membranes longer than 18 hours
  • Maternal fever > 100.4

The recommended antibiotic for prevention of GBS is Penicillin or Amoxicillin. If you have an allergy to either one of these medications, please inform your provider. Additional testing for antibiotic resistance is recommended to ensure that you receive the most effective antibiotic available.