Definition

Group B streptococcal (GBS) disease is a bacterial infection.

GBS can cause illness in newborn babies, pregnant women, the elderly, and adults with other chronic medical conditions, such as diabetes or liver disease. In newborns, it is the most common cause of a blood infection called sepsis and of meningitis, which is an infection of the fluid and lining surrounding the brain.

This following information covers GBS in pregnant women and their babies.

Causes

GBS is caused by specific bacteria. These bacteria live in the gastrointestinal and genital tracts. They are found in the vaginal or rectal areas of 10% to 35% of all healthy adult women. Only a small number of babies who are exposed to the bacteria will become infected. If infection occurs, it can be serious.

Newborn babies can become infected with GBS in 3 ways:

• Before birth, bacteria in the vagina can spread up the birth canal into the uterus and infect the amniotic fluid surrounding the fetus. The baby becomes infected by inhaling the infected fluid.
• During delivery, by contact with bacteria in the birth canal
• After birth, by close physical contact with the mother

Risk Factors

Factors that may increase your baby’s chance of GBS include:

• Mother currently has GBS in her vaginal or rectal area—This is confirmed by a lab test between weeks 35-37 of pregnancy.
• Mother is GBS positive and does not get antibiotics at least 4 hours before delivery
• Mother had a previous baby with GBS disease
• Mother has a urinary tract infection due to GBS
• Labor or rupture of the membranes before 37 weeks of pregnancy
• Rupture of the membranes for 18 hours or more before delivery
• Mother has a fever during labor
• Frequent vaginal examinations during labor
• Use of intrauterine fetal monitoring devices

Symptoms

In pregnant women, GBS infections can sometimes cause inflammation or irritation of the lining of the uterus called endometritis, infection of the uterus and amniotic sac called amnionitis, and loss of pregnancy due to infection.

Symptoms of endometritis and amnionitis may include:

• Fever
• Abdominal pain
• Bad odor of amniotic fluid

Doctors are especially concerned about how GBS infections affect young infants. The disease can occur early in newborns (early-onset) or late (late-onset). Early-onset GBS disease usually causes illness within the first 24 hours of life. However, illness can occur up to 3 days after birth. Late-onset disease usually occurs at 3 to 4 weeks of age. It can occur any time from 4 days to 3 months of age.

Symptoms of GBS include:

• Unstable temperature—low or high
• Breathing problems
• Not eating well
• Irritability
• Difficulty waking
• Weakness or lacking energy—in late-onset disease

Diagnosis

GBS can be diagnosed in a pregnant woman at an obstetric office visit. Testing for GBS should be done about one month before the baby is due. The doctor swabs the vagina and rectum and sends this sample to a laboratory to test for GBS. Test results are available in 24-48 hours. Treatment usually does not begin until labor starts.

Your baby’s bodily fluids may be tested. This can be done with:

• Blood tests
• Culture tests
• Urine tests
• Spinal fluid test

Treatment

Prevention

Methods to prevent GBS may include:

• Screening pregnant women at 35-37 weeks—If GBS is found through the screening, IV antibiotics are given during labor and delivery.
• For women who did not receive screening at 35-37 weeks, an alternate strategy gives antibiotics during labor and delivery to women who:
  • Are carriers of GBS bacteria
  • Have previously had an infant with GBS disease
  • Have GBS bacterium at any time during the present pregnancy
  • Go into labor or have rupture of the membranes before the fetus has reached an estimated gestational age of 37 weeks
  • Have rupture of membranes for 18 hours or more before delivery
  • Have a fever during labor
  • Have a urinary tract infection with GBS

Group B Strep Association http://www.groupbstrep.org

Women’s Health Matters http://www.womenshealthmatters.ca/

Group B strep (GBS). Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/groupbstrep/index.html
Updated May 23, 2011. Accessed June 19, 2014.

Group B strep infection: GBS. American Pregnancy Association website. Available at:
http://americanpregnancy.org/pregnancy-complications/group-b-strep-infection
Updated March 2011. Accessed June 19, 2014.

Group B streptococcal infection in infants less than 3 months old. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated May 19, 2014. Accessed June 19, 2014.

Ohlsson A, Shah VS. Intrapartum antibiotics for known maternal Group B streptococcal colonization. Cochrane Database Syst Rev. 2009;(3):CD007467.

Provisional Recommendations for the Prevention of Perinatal Group B Streptococcal Disease. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/groupbstrep/guidelines/downloads/provisional-recommendations-508.pdf
Updated July 2010. Accessed August 14, 2013.

Puopolo KM, Madoff LC, Eichenwald EC. Early-onset Group B streptococcal disease in the era of maternal screening. Pediatrics. 2005;115(5):1240-1246.

Woodgate P, Flenady V, Steer P. Intramuscular penicillin for the prevention of early onset Group B streptococcal infection in newborn infants. Cochrane Database Syst Rev. 2004;(3):CD003667.