Group B Strep – Assess Your Risk to Make an Informed Decision

Streptococcus Agalactiae, more commonly known as Group B strep (GBS) is a type of bacteria that pregnant women are screened for during the later stages of their pregnancy.

In Australia, in most cases if a woman tests positive, she will be administered antibiotics during labour to reduce the risk of passing it onto baby when they come through the birth canal. If it is passed on, the infant can develop early onset group b strep (EOGBS) which in very rare cases can be fatal.

Whilst this approach could be viewed as a risk prevention model, there are other factors that should be considered when making this decision. Unfortunately in the mainstream medical world, sometimes information relayed to the pregnant woman can be cherry picked based on what the preferred outcome of the hospital or healthcare provider is. 

My aim is to provide information that covers all bases so you can make an informed choice and one that you feel truly comfortable with.

Clearing Up Some Facts

Firstly, let’s clear a couple of things up about GBS. Bacteria in general reside in and on our bodies and can be referred to as beneficial, pathogenic, or mutual. Some bacteria appear to live in or on their human host without seeming to do anything particularly helpful or harmful. This is known as commensal bacteria, and it is important to note that this is what GBS is classified as. This bacteria can occasionally cause urine and uterine infections in women and these are a couple of the risk factors that should be taken into consideration when making an informed choice about your course of action. In rare instances a commensal carrier can transmute into a pathogenic infection, and this is where the risk lies.  Keep reading for more risk factors worth assessing.

Because GBS can reside in the vagina and rectum, it can be passed to the baby during birth. It is important to note that the passing of mama’s microbes to baby during the birthing process is a normal and healthy event that helps set up the baby’s microbiome and ultimately their immune system. 

The Importance of Language

So before I go any further I believe it is necessary to point out that the language we use around this topic is very influential when it comes to how it is received by a lay person (or a heavily pregnant woman who is already feeling anxious). For example, words like ‘disease’ and ‘infection’ denote negative connotations and a sense of fear right from the get go. Whilst these words are appropriate when the rare instance of an infant becoming ill from GBS occurs, perhaps the terminology should be reassessed to paint a more accurate picture. 

As mentioned above, commensal bacteria are usually benign and tend to iterate, so the term ‘infection’ when the bacteria is picked up on a pregnant woman, is not completely accurate. A word like ‘carrier’ may be more precise (and less anxiety provoking).

A Summary of Stats & Research

Whenever we are trying to make an informed decision, looking at past research is a great place to start. Here is a summary of some important findings of research on this topic and I have included references at the end of this article.

  • Kalin et al found that 1 in 27000 women were seriously affected by GBS disease. 
  • They also found that 79% of babies born to women who experienced severe sepsis did not themselves develop the infection.
  • Bevan et al demonstrated that 89.4-96% of babies diagnosed with EOGBS survive 
  • In absence of risk, the chance of adverse outcome is extremely low (1 in 5000 chance of contacting/ 1 in 40,000 of death/illness).
  • Seedat et al concluded “current approach to screen positive women would lead to 99.8% receiving unnecessary intrapartum antibiotics.”
  • The epidemiology of early onset neonatal sepsis in Australia and New Zealand from 2002-2012 showed that the incidence rate for GBS was 0.43/1000 live births.
  • Homer et al showed that without antibiotic intervention, the prevalence of EOGBS in Australia, United States and Western Europe has been estimated between 0.4-4 per 1000 live births.
  • The National Screening Committee for GBS does not recommend universal screening because there is no clear evidence that routine testing does more good than harm. They state that many women carry the bacteria and their babies are born safely and without developing the infection
  • Florindo et al showed that 17 to 25% of women who were GBS positive at 35-37 weeks will be negative at time of delivery.
  • The US based Centres for Disease Control showed that babies born before 33 weeks are at greater risk of developing a GBS infection (20-30%) but the survival rate increases as the gestational age increases.

In summary, these collated findings show that the likelihood of newborns developing serious sepsis and/or death is very low and that a lot of the time intrapartum antibiotic prescription in Australia is unnecessary. Despite this, it is still important to outline what could happen if a newborn developed a GBS infection. They could experience symptoms such as fevers, difficulty feeding, lethargy and irritability, with the risk of also developing illnesses such as pneumonia and meningitis. The usual standard of care involves intravenous antibiotics.

Risk Factors To Consider

Australia and the United States follow a ‘culture based’ model which means that GBS testing is a routine part of pregnancy screening. However, it is completely up to the woman if she wants to have the test. In the UK and New Zealand, however, their approach is a risk based model which means that they only carry out the test if the woman presents with relevant risks and symptoms. 

The main symptoms and risk factors that should be taken into consideration include:

  • Pregnancy symptoms: high temperature, uterine pain, UTIs or unusual vaginal discharge;
  • Gestational age: preterm babies are more susceptible to EOGBS;
  • Birth history (where relevant): duration of labour and birth; relatively short labours and births are lower risk factors, especially if the time from waters breaking to birth is shorter’
  • GBS history: prior diagnosis with previous pregnancies.

Other Impacts of Intrapartum Antibiotics

Something that is not largely talked about in the medical world is the after effects of antibiotics and how this can impact the health of mama and bub. Whilst antibiotics can sometimes be effective at targeting pathogenic bacteria, they also destroy beneficial bacteria, and can have a detrimental impact on mum’s microbiome, which will have a knock-on effect to the initial seeding of baby’s microbiome. This can lead to immune system development issues for the child in the future.

Natural GBS Solutions 

Our bodies have an amazing ability to find a more homeostatic point especially when we give it some assistance. And thankfully mother nature provides us with some amazing pregnancy safe immune boosting and antibacterial solutions.

My three go to’s to help support your body if you do find out you are carrying GBS during pregnancy:

  1. Raw garlic – contains allicin which has amazing antibacterial properties. Simply brew 1 clove in warm water with manuka honey and lemon;
  2. Kakadu Plum powder – high in vitamin c. Take 1 teaspoon twice daily in filtered water;
  3. Probiotics (L. Rueteri or L. Salivarius). Take 1 capsule twice daily.

In conclusion, the main things to note are that GBS is a commensal bacteria that mostly just comes and goes. It should be normalised more, especially when it comes to the language used when relaying information to a pregnant woman. If you have had a low risk pregnancy and consider yourself a healthy individual you absolutely have the right to decline the screen and continue to have a healthy and nourished pregnancy. If you are experiencing any of the symptoms mentioned above then it may be worth considering the screening or perhaps even the antibiotics, especially if you find out you are a carrier. If you are a first time mama and do not have any previous births or labours to compare it to I would consider asking your own mum what her birth journey was like.

Hopefully you have found this article informative and helpful. Please contact me if you’d like some more information. I offer 15 minute complimentary consultations and would love to hear from you!


  1. Zhong, H., Penders, J., Shi, Z. et al. Impact of early events and lifestyle on the gut microbiota and metabolic phenotypes in young school-age children. Microbiome 7, 2 (2019).

  2. Kalin A, Acosta C, Kurinczuk JJ, Brocklehurst P, Knight M. Severe sepsis in women with group B Streptococcus in pregnancy: an exploratory UK national case-control study. BMJ Open. 2015;5(10):e007976. Published 2015 Oct 8. https://doi:10.1136/bmjopen-2015-007976

  3. Bevan D, White A, Marshall J, Peckham C. Modelling the effect of the introduction of antenatal screening for group B Streptococcus (GBS) carriage in the UK. BMJ Open. 2019;9(3):e024324. Published 2019 Mar 23. https://doi:10.1136/bmjopen-2018-024324

  4. Seedat F, Geppert J, Stinton C, et al. Universal antenatal screening for group B streptococcus may cause more harm than good. BMJ. 2019;364:l463. Published 2019 Feb 20. https://doi:10.1136/bmj.l463

  5. Caroline S.E. Homer, Vanessa Scarf, Christine Catling, Deborah Davis. Culture-based versus risk-based screening for the prevention of group B streptococcal disease in newborns: A review of national guidelines. Women and Birth, Volume 27, Issue 1,2014, Pages 46-51.

  6. Singh T, Barnes EH, Isaacs D Australian Study Group for Neonatal InfectionsEarly-onset neonatal infections in Australia and New Zealand, 2002–2012Archives of Disease in Childhood – Fetal and Neonatal Edition 2019;104:F248-F252.

  7. Florindo C, Damião V, Lima J, et al. Accuracy of prenatal culture in predicting intrapartum group B streptococcus colonization status. J Matern Fetal Neonatal Med. 2014;27(6):640-642. https://doi:10.3109/14767058.2013.820700

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