Group B Strep (GBS)

Overview As a parent or parent-to-be, you’ve probably come across the name Group B Strep which is a common bacteria carried within the body. Although Group B Strep is mostly harmless in adults, there are …

Illustration of Group B Strep (GBS)
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As a parent or parent-to-be, you’ve probably come across the name Group B Strep which is a common bacteria carried within the body. Although Group B Strep is mostly harmless in adults, there are a few things to look out for. 

What is Group B Strep (GBS)?

GBS takes the form of a bacteria known as streptococcal bacteria and usually occurs in the rectum or vaginal areas, gastrointestinal tracts, and less frequently, the upper respiratory tract of children and adults. It’s estimated that between 20% and 40% of adult women carry the bacteria at any given time without being aware of it or suffering any negative effects.

Although Group B Strep can occur naturally in the body, it is also transmissible and can be passed on through contact such as hand to hand, skin to skin, and through kissing and intimacy. It is an important cause of illness in neonates, young infants, pregnant women, and adults with underlying medical conditions.

GBS and pregnancy

GBS can cause complications during pregnancy and childbirth. Medical professionals generally don’t test for GBS as routine during pregnancy though. Even when screening does occur, it is often inaccurate.

As mentioned, GBS can be carried in the body without any adverse effects. But in some cases, it can cause infections in unborn children, which can lead to more serious conditions such as meningitis, pneumonia, or sepsis if left untreated. There is no clear association between maternal GBS colonization during pregnancy and preterm delivery, but GBS does cause third-trimester stillbirths.

Typically, this condition is only detected by chance during vaginal, rectal, or urine tests performed for other reasons.  If an infection in an unborn child is detected during normal testing, it can be treated with antibiotics during labor, which is usually highly effective. Although some people feel that, because of this, antibiotics should be given to pregnant women as standard, experts consider the risk to mother and baby would outweigh the risk of a potential GBS infection. 

While testing is not standard, concerned parents should speak to their doctor or medical professional if they are worried about the possibility of an infection in their unborn child. In particular, a woman who has previously had a baby which was born with a GBS infection should always make her healthcare professionals aware of this. In this case, antibiotics will usually be prescribed as a safeguard.

GBS and newborns

Within the United States, around 930 babies suffer from early-onset GBS infections each year. Around 1050 suffer from late-onset infections, so it is extremely rare for Group B Strep to lead to serious illness. 

It is, however, possible for a child to come into contact with Group B Strep during labor and birth. This carries an increased risk of infection, particularly of meningitis, which can occur between one week and several months after birth. 

Meningitis is an infection of the protective membranes around the brain and spinal cord. If left untreated, it can lead to permanent brain or nerve damage and septicemia, which can be life-threatening. 


What are the symptoms of Group B Strep in pregnant women? When it does cause symptoms, the symptoms depend on the organs involved. Common types of GBS infection include:

  • Bladder infection – The symptoms of a bladder infection include:
    • Pain or a burning feeling when you urinate
    • The need to urinate often
    • The need to urinate suddenly or in a hurry
    • Blood in the urine
  • Kidney infection – The symptoms of a kidney infection can include the symptoms of a bladder infection, but they can also include fever, back pain, and nausea and vomiting.
  • Amniotic infection (also called intra-amniotic infection) – The symptoms of an amniotic infection include:
    • Fever
    • Tenderness in the lower part of the belly, where the uterus is found
    • A fast heart rate in the mother or the fetus (unborn baby)

What are the symptoms of Group B Strep in babies? As a parent, there are a few things you can look out for if you’re concerned that your baby may have a GBS infection. Some of these are: 

  • Noisy breathing, grunting or moaning
  • Baby’s chest or stomach shows signs that they are working hard to breathe
  • Excessive sleepiness
  • Excessive crying
  • Feeding poorly or unable to keep milk down
  • Dramatic changes in skin temperature – skin may feel hot or cold to the touch
  • Changes in skin color and unusual blotches
  • Changes in heart and breathing rate
  • Baby is floppy or unresponsive

If your baby is displaying one or more of these symptoms, you should contact your healthcare professional immediately.

Diagnosis and treatment of Group B Strep

Your healthcare professional will usually perform a blood test and/or a lumbar puncture to ascertain whether or not your baby has a Group B Strep infection. If the test is positive, the infection will generally be treated with antibiotics. The doctor will usually re-test the baby after 36 hours and will continue until all tests are returned with a negative result. 

While it’s natural for parents to worry about infections in unborn children and newborns, it’s extremely rare for GBS to lead to infections and more serious diseases.  Having said that, it’s a good idea to get into the habit of checking for the symptoms mentioned in this article and to seek immediate help if you have any concerns.

Although there is currently no vaccine to prevent GBS at the moment, implementing a vaccine for pregnant women is a promising strategy to prevent neonatal and infant GBS disease and has been identified as a priority by the World Health Organisation. Protein vaccines are in earlier stages of development but are highly promising and may protect against all strains of GBS.

  1. Edwards MS, Nizet V, Baker CJ. Group B Streptococcal Infections. In: Infectious Diseases of the Fetus and Newborn Infant, 7th ed, Remington JS, Klein JO, Wilson CB, et al (Eds), Elsevier Saunders, Philadelphia 2011. P.419.
  2. Eichenwald EC. Perinatally transmitted neonatal bacterial infections. Infect Dis Clin North Am 1997; 11:223.
  3. Verani JR, McGee L, Schrag SJ, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC). Prevention of perinatal group B streptococcal disease–revised guidelines from CDC, 2010. MMWR Recomm Rep 2010; 59:1.
  4. Phares CR, Lynfield R, Farley MM, et al. Epidemiology of invasive group B streptococcal disease in the United States, 1999-2005. JAMA 2008; 299:2056.
  5. Valkenburg-van den Berg AW, Sprij AJ, Dekker FW, et al. Association between colonization with Group B Streptococcus and preterm delivery: a systematic review. Acta Obstet Gynecol Scand 2009; 88:958.
  6. Seale AC, Bianchi-Jassir F, Russell NJ, et al. Estimates of the Burden of Group B Streptococcal Disease Worldwide for Pregnant Women, Stillbirths, and Children. Clin Infect Dis 2017; 65:S200.
  7. World Health Organization (WHO). WHO preferred product characteristics for Group B Streptococcus vaccines. 2017;18 Available from: Accessed March16, 2020.
  8. Carreras-Abad, C., Ramkhelawon, L., Heath, P. T., & Le Doare, K. (2020). A Vaccine Against Group B Streptococcus: Recent Advances. Infection and drug resistance, 13, 1263–1272.
  9. Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 797. Obstet Gynecol 2020; 135:e51.

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